diff --git a/README.md b/README.md
index d498d5b0..bfdd5809 100644
--- a/README.md
+++ b/README.md
@@ -23,17 +23,18 @@ cp config.template.ios.json config.json
 
 You can edit the config file as suited:
 
-| Parameter          | Description                      |
-| --------------     | ---------------------------------|
-| `baseUrl`          | Ylitse API base URL              |
-| `loginUrl`         | Ylitse service login URL         |
-| `feedBackUrl`      | Feedback form URL                |
-| `termsUrl`         | Terms and conditions URL         |
-| `userGuideUrl`     | User's manual URL                |
-| `apuuUrl`          | Apuu-chat URL                    |
-| `sekasinUrl`       | Sekasin-chat URL                 |
-| `saferSpaceUrl`    | Principals of a safer space URL  |
-| `messageFetchDelay`| Delay between polling            |
+| Parameter          | Description                            |
+| -----------------  | ---------------------------------------|
+| `baseUrl`          | Ylitse API base URL                    |
+| `loginUrl`         | Ylitse service login URL               |
+| `feedBackUrl`      | Feedback form URL                      |
+| `termsUrl`         | Terms and conditions URL               |
+| `userGuideUrl`     | User's manual URL                      |
+| `apuuUrl`          | Apuu-chat URL                          |
+| `sekasinUrl`       | Sekasin-chat URL                       |
+| `saferSpaceUrl`    | Principals of a safer space URL        |
+| `storeUrl`         | App marketplace URL (build specific)   |
+| `messageFetchDelay`| Delay between polling                  |
 
 
 ### Running on iOS
@@ -92,22 +93,7 @@ npx react-native run-android
 
 ### Debugging
 
-We are using [Flipper](https://fbflipper.com/) for debugging, so install the [Desktop application](https://fbflipper.com/docs/getting-started/) to your environment
-
-1. Run the application
-2. Open [Flipper](https://fbflipper.com/docs/getting-started/#setup-your-react-native-app)
-3. Install plugin [redux-debugger](https://github.com/jk-gan/flipper-plugin-redux-debugger)
-4. Now you should see all logs, networking and redux things in the Flipper tool
-
-For troubleshooting, please refer to the [Flipper documentation](https://fbflipper.com/docs/getting-started/troubleshooting/)
-
-#### Fixing issue when running API locally
-Setup adb reverse connections:
-```sh
-adb reverse tcp:8081 tcp:8081; adb reverse tcp:8080 tcp:8080
-```
-
-
+Follow the instructions to use the [hermes debugger](https://reactnative.dev/docs/debugging?js-debugger=hermes)
 
 ### Running end-to-end tests
 
@@ -163,3 +149,13 @@ Replace the moustached values with your values
 - If you get error ==ReferenceError: fetch is not defined== then you are not running the tests with npm 18, which ships with fetch. Refer to the _Node version_ section of this README
 
 - If you get error ==ECONNREFUSED== then you are probably using localhost as a value for the ${YLITSE_API_URL} env-variable. Replace localhost with 127.0.0.1
+
+- If you get error connecting to local API:
+
+Setup adb reverse connections:
+```sh
+adb reverse tcp:8081 tcp:8081; adb reverse tcp:8080 tcp:8080
+```
+
+
+
diff --git a/android/app/build.gradle b/android/app/build.gradle
index 19775faa..47d2cecd 100755
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -105,8 +105,8 @@ android {
         applicationId "com.ylitse"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 48
-        versionName "2.14.0"
+        versionCode 49
+        versionName "2.15.0"
         testBuildType System.getProperty('testBuildType', 'debug')  // This will later be used to control the test apk build type
         testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
     }
diff --git a/appcenter-pre-build.sh b/appcenter-pre-build.sh
index 76d8e472..8bf5ee48 100644
--- a/appcenter-pre-build.sh
+++ b/appcenter-pre-build.sh
@@ -12,6 +12,7 @@ tee config.json > /dev/null <<EOF
     "userGuideUrl": "$YLITSE_USERGUIDEURL",
     "apuuUrl": "$YLITSE_APUUURL",
     "sekasinUrl": "$YLITSE_SEKASINURL",
+    "storeUrl": "$YLITSE_STOREURL",
     "saferSpaceUrl": "$YLITSE_SAFERSPACEURL",
     "messageFetchDelay": $YLITSE_MESSAGEFETCHDELAY
 }
diff --git a/config.template.android.json b/config.template.android.json
index 02095475..4c309c6d 100644
--- a/config.template.android.json
+++ b/config.template.android.json
@@ -7,5 +7,6 @@
   "apuuUrl": "http://10.0.2.2:3000",
   "sekasinUrl": "http://10.0.2.2:3000",
   "saferSpaceUrl": "http://10.0.2.2:3000",
+  "storeUrl":"http://localhost:3000", 
   "messageFetchDelay": 2000
 }
diff --git a/config.template.ios.json b/config.template.ios.json
index db3a1ec4..08b01d78 100644
--- a/config.template.ios.json
+++ b/config.template.ios.json
@@ -6,6 +6,7 @@
   "userGuideUrl": "http://localhost:3000",
   "apuuUrl": "http://localhost:3000",
   "sekasinUrl": "http://localhost:3000",
+  "storeUrl":"http://localhost:3000", 
   "saferSpaceUrl": "http://10.0.2.2:3000",
   "messageFetchDelay": 2000
 }
diff --git a/src/Screens/Main/Tabs.tsx b/src/Screens/Main/Tabs.tsx
index 8491af85..9177c69d 100644
--- a/src/Screens/Main/Tabs.tsx
+++ b/src/Screens/Main/Tabs.tsx
@@ -1,13 +1,20 @@
 import React from 'react';
+import * as RN from 'react-native';
 
 import * as ReactRedux from 'react-redux';
+import * as redux from 'redux';
 import { selectFirstQuestion } from '../../state/reducers/questions';
 
+import { selectIsVersionBigEnough } from '../../state/reducers/minimumVersion';
+import { storeUrl } from '../../api/config';
 import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';
+import * as actions from '../../state/actions';
+
 import { StackScreenProps } from '@react-navigation/stack';
 import { CommonActions } from '@react-navigation/native';
 import { StackRoutes } from '..';
-import { useRefetch } from 'src/lib/use-refetch';
+import { useRefetch } from '../../lib/use-refetch';
+import { getClient } from '../../lib/isDevice';
 
 import BuddyList, { BuddyListRoute } from './BuddyList';
 import MentorList, { MentorListRoute } from './MentorList';
@@ -16,6 +23,7 @@ import Settings, { SettingsRoute } from './Settings';
 import QuestionModal from '../components/QuestionModal';
 import { Answer } from '../../api/feedback';
 import { TabBar } from './TabBar';
+import Modal from '../components/Modal';
 
 export type TabsRoute = {
   'Main/Tabs': {
@@ -30,9 +38,13 @@ const Tab = createBottomTabNavigator<TabRoutes>();
 type Props = {} & StackScreenProps<StackRoutes, 'Main/Tabs'>;
 
 const Main = ({ navigation, route }: Props) => {
-  const dispatch = ReactRedux.useDispatch();
-
+  const dispatch = ReactRedux.useDispatch<redux.Dispatch<actions.Action>>();
   const initialRouteName = route.params?.initial;
+  const appClient = getClient();
+
+  const isAppVersionBigEnough = ReactRedux.useSelector(
+    selectIsVersionBigEnough(appClient),
+  );
 
   const handleRefetchData = () => {
     dispatch({ type: 'feedback/getQuestions/start', payload: undefined });
@@ -53,6 +65,8 @@ const Main = ({ navigation, route }: Props) => {
     callback: handleRefetchData,
   });
 
+  const openStore = () => RN.Linking.openURL(storeUrl);
+
   React.useEffect(() => {
     navigation.dispatch(state => {
       const routes = state.routes.filter(r => !r.name.includes('Onboarding'));
@@ -65,6 +79,10 @@ const Main = ({ navigation, route }: Props) => {
     });
   }, []);
 
+  React.useEffect(() => {
+    dispatch({ type: 'minimumVersion/get/start', payload: undefined });
+  }, []);
+
   return (
     <>
       <Tab.Navigator
@@ -83,6 +101,15 @@ const Main = ({ navigation, route }: Props) => {
           onAnswer={handleAnswer}
         />
       )}
+      {!isAppVersionBigEnough && (
+        <Modal
+          modalType="danger"
+          title="main.version.not.big.enough.title"
+          messageId="main.version.not.big.enough.text"
+          primaryButtonMessage="main.version.not.big.enough.button"
+          onPrimaryPress={openStore}
+        />
+      )}
     </>
   );
 };
diff --git a/src/Screens/components/Modal/index.tsx b/src/Screens/components/Modal/index.tsx
index 39a8e4d2..fd0bba4b 100644
--- a/src/Screens/components/Modal/index.tsx
+++ b/src/Screens/components/Modal/index.tsx
@@ -36,49 +36,44 @@ const Modal: React.FC<Props> = props => {
   } as const;
 
   return (
-    <RN.View style={styles.container}>
-      <RN.Modal animationType="fade" transparent={true} visible={true}>
-        <RN.View style={styles.background}>
-          <RN.View style={[props.style, styles.modalContainer]}>
-            <RN.View style={[styles.titleContainer, { backgroundColor }]}>
-              <RN.Image style={styles.image} source={icon} />
-              <Message id={props.title} style={styles.title} />
-            </RN.View>
+    <RN.Modal animationType="fade" transparent={true} visible={true}>
+      <RN.View style={styles.background}>
+        <RN.View style={[props.style, styles.modalContainer]}>
+          <RN.View style={[styles.titleContainer, { backgroundColor }]}>
+            <RN.Image style={styles.image} source={icon} />
+            <Message id={props.title} style={styles.title} />
+          </RN.View>
 
-            <RN.View style={styles.textContainer}>
-              <Message id={props.messageId} style={styles.text} />
-            </RN.View>
+          <RN.View style={styles.textContainer}>
+            <Message id={props.messageId} style={styles.text} />
+          </RN.View>
 
-            <RN.View style={[styles.buttonContainer, justifyButtons]}>
-              {props.onSecondaryPress && (
-                <Button
-                  onPress={props.onSecondaryPress}
-                  messageId={props.secondaryButtonMessage ?? 'meta.ok'}
-                  style={[styles.button, styles.secondaryButton]}
-                  emphasis="medium"
-                />
-              )}
-              {props.onPrimaryPress && (
-                <Button
-                  onPress={props.onPrimaryPress}
-                  messageId={
-                    props.primaryButtonMessage ?? 'components.remoteData.retry'
-                  }
-                  style={[styles.button, styles.primaryButton]}
-                />
-              )}
-            </RN.View>
+          <RN.View style={[styles.buttonContainer, justifyButtons]}>
+            {props.onSecondaryPress && (
+              <Button
+                onPress={props.onSecondaryPress}
+                messageId={props.secondaryButtonMessage ?? 'meta.ok'}
+                style={[styles.button, styles.secondaryButton]}
+                emphasis="medium"
+              />
+            )}
+            {props.onPrimaryPress && (
+              <Button
+                onPress={props.onPrimaryPress}
+                messageId={
+                  props.primaryButtonMessage ?? 'components.remoteData.retry'
+                }
+                style={[styles.button, styles.primaryButton]}
+              />
+            )}
           </RN.View>
         </RN.View>
-      </RN.Modal>
-    </RN.View>
+      </RN.View>
+    </RN.Modal>
   );
 };
 
 const styles = RN.StyleSheet.create({
-  container: {
-    flex: 1,
-  },
   background: {
     backgroundColor: colors.transparentBlack,
     position: 'absolute',
diff --git a/src/api/config.ts b/src/api/config.ts
index b1dd0e50..7b79370d 100644
--- a/src/api/config.ts
+++ b/src/api/config.ts
@@ -9,3 +9,4 @@ export const apuuUrl = config.apuuUrl;
 export const sekasinUrl = config.sekasinUrl;
 export const saferSpaceUrl = config.saferSpaceUrl;
 export const messageFetchDelay = config.messageFetchDelay;
+export const storeUrl = config.storeUrl;
diff --git a/src/api/minimumVersion.ts b/src/api/minimumVersion.ts
new file mode 100644
index 00000000..9ff56aa5
--- /dev/null
+++ b/src/api/minimumVersion.ts
@@ -0,0 +1,50 @@
+import * as t from 'io-ts';
+import * as TE from 'fp-ts/lib/TaskEither';
+
+import * as http from '../lib/http';
+
+import * as config from './config';
+import * as authApi from './auth';
+import { ValidVersion } from '../lib/validators';
+
+const client = t.strict({
+  client: t.string,
+  version: ValidVersion,
+});
+
+type Client = t.TypeOf<typeof client>;
+
+const clientVersions = t.array(client);
+
+const versionsResponse = t.strict({
+  resources: clientVersions,
+});
+
+export type AppClient = {
+  client: string;
+  major: number;
+  minor: number;
+  patch: number;
+};
+
+export const toAppClient = (value: Client): AppClient => {
+  const [major, minor, patch] = value.version.split('.').map(Number);
+
+  return {
+    client: value.client,
+    major,
+    minor,
+    patch,
+  };
+};
+
+export const fetchVersions = (
+  token: authApi.AccessToken,
+): TE.TaskEither<string, Array<AppClient>> =>
+  http.validateResponse(
+    http.get(`${config.baseUrl}/version/clients`, {
+      headers: authApi.authHeader(token),
+    }),
+    versionsResponse,
+    response => response.resources.map(toAppClient),
+  );
diff --git a/src/lib/__tests__/validators.ts b/src/lib/__tests__/validators.ts
index 10326c0d..522a3819 100644
--- a/src/lib/__tests__/validators.ts
+++ b/src/lib/__tests__/validators.ts
@@ -108,15 +108,49 @@ describe('Validate The valid password to be true', () => {
   });
 });
 
-describe('Validate The invalid password to be true', () => {
+describe('Validate The invalid password', () => {
   [
     '',
     'password22',
     'PasswordSalasana',
     'ÄteritsiputeRitsipuolilautatsijänk',
   ].forEach(password => {
-    it(`decodes valid password ${password}`, () => {
+    it(`decodes inValid password ${password}`, () => {
       expect(isLeft(validators.ValidPassword.decode(password))).toEqual(true);
     });
   });
 });
+
+describe('Validate correct versions', () => {
+  ['1.23.3', '10.20.0', '3.99.99', '2.11.1', '3.110.5'].forEach(version => {
+    it(`decodes valid  version ${version}`, () => {
+      expect(isRight(validators.ValidVersion.decode(version))).toEqual(true);
+    });
+  });
+});
+
+describe('Validate invalid versions', () => {
+  [
+    '1.2',
+    '1.2.3.4',
+    '01.2.3',
+    '1.2.03',
+    'a.b.c',
+    '1.2.a',
+    '',
+    '1..2',
+    '.1.2.3',
+    '1.2.3.',
+    '1.2.',
+    '1..',
+    '1',
+    null,
+    undefined,
+    123,
+    {},
+  ].forEach(version => {
+    it(`invalidates invalid version ${version}`, () => {
+      expect(isLeft(validators.ValidVersion.decode(version))).toEqual(true);
+    });
+  });
+});
diff --git a/src/lib/isDevice.ts b/src/lib/isDevice.ts
index df7f15a1..23eefcf4 100644
--- a/src/lib/isDevice.ts
+++ b/src/lib/isDevice.ts
@@ -1,8 +1,16 @@
 import RN from 'react-native';
 import { PlatformOSType } from 'react-native/types';
 import Device from 'react-native-device-info';
+import { toAppClient } from '../api/minimumVersion';
 
 export const isDevice = (platform: PlatformOSType) =>
   platform === RN.Platform.OS;
 
 export const hasNotch = () => Device.hasNotch();
+
+export const getClient = () => {
+  const version = Device.getVersion();
+  const client = RN.Platform.OS === 'android' ? 'ylitse_android' : 'ylitse_ios';
+
+  return toAppClient({ version, client });
+};
diff --git a/src/lib/validators.ts b/src/lib/validators.ts
index 303543ce..e263d0fa 100644
--- a/src/lib/validators.ts
+++ b/src/lib/validators.ts
@@ -52,6 +52,10 @@ export const isValidDescription = (value: string): boolean => {
   return /^(?!\s*$).+/.test(value);
 };
 
+const isValidVersion = (value: string): boolean => {
+  return /^\d+\.\d+\.\d+$/.test(value);
+};
+
 export const ValidEmail = new t.Type<string, string, unknown>(
   'ValidEmail',
   (input: unknown): input is string => typeof input === 'string',
@@ -91,3 +95,19 @@ export const ValidPassword = new t.Type<string, string, unknown>(
       : t.failure(input, context),
   t.identity,
 );
+
+export const ValidVersion = new t.Type<string, string, unknown>(
+  'ValidVersion',
+  (input: unknown): input is string => typeof input === 'string',
+  (input, context) =>
+    either.chain(t.string.validate(input, context), str => {
+      const noLeadingZeros = str
+        .split('.')
+        .every(part => part === '0' || !part.startsWith('0'));
+
+      return isValidVersion(str) && noLeadingZeros
+        ? t.success(str)
+        : t.failure(input, context);
+    }),
+  t.identity,
+);
diff --git a/src/localization/en.ts b/src/localization/en.ts
index 3ac01472..0d466528 100644
--- a/src/localization/en.ts
+++ b/src/localization/en.ts
@@ -159,6 +159,11 @@ export const messages: { [key in MessageId]: string } = {
     'SOS-Lapsikylä representative will contact you after the investigation.',
   'main.userreport.title': 'Report',
 
+  'main.version.not.big.enough.button': 'Update',
+  'main.version.not.big.enough.text':
+    'An update is necessary to continue using the app. Click below to download the latest version.',
+  'main.version.not.big.enough.title': 'Update required',
+
   'meta.back': 'Back',
   'meta.blank': ' ',
   'meta.cancel': 'Cancel',
diff --git a/src/localization/fi.ts b/src/localization/fi.ts
index 3565f01d..ec71396d 100644
--- a/src/localization/fi.ts
+++ b/src/localization/fi.ts
@@ -159,6 +159,11 @@ export const messages = {
     'SOS-Lapsikylän työntekijä selvittää tilanteen ja ottaa sinuun yhteyttä.',
   'main.userreport.title': 'Ilmianna',
 
+  'main.version.not.big.enough.button': 'Päivitä nyt',
+  'main.version.not.big.enough.text':
+    'Päivitys on tarpeen sovelluksen käytön jatkamiseksi. Napsauta alla olevaa painiketta ladataksesi uusimman version',
+  'main.version.not.big.enough.title': 'Päivitys saatavilla',
+
   'meta.back': 'Takaisin',
   'meta.blank': ' ',
   'meta.cancel': 'Peru',
diff --git a/src/state/actions/regular.ts b/src/state/actions/regular.ts
index b16deb50..3fab6bce 100644
--- a/src/state/actions/regular.ts
+++ b/src/state/actions/regular.ts
@@ -10,6 +10,7 @@ import * as messageApi from '../../api/messages';
 import * as statApi from '../../api/stat';
 import * as userReportApi from '../../api/userReport';
 import * as feedbackApi from '../../api/feedback';
+import * as minimumVersionApi from '../../api/minimumVersion';
 import * as messages from '../reducers/messages';
 import * as updateMentorData from '../reducers/updateMentorData';
 
@@ -126,6 +127,9 @@ type RegularActions = {
   'feedback/sendAnswer/start': feedbackApi.Answer;
   'feedback/sendAnswer/end': Result<ReturnType<typeof feedbackApi.sendAnswer>>;
   'feedback/reset/': undefined;
+
+  'minimumVersion/get/start': undefined;
+  'minimumVersion/get/end': Result<typeof minimumVersionApi.fetchVersions>;
 };
 
 // TODO name plz.
diff --git a/src/state/reducers/index.ts b/src/state/reducers/index.ts
index 34ec2345..c765637e 100644
--- a/src/state/reducers/index.ts
+++ b/src/state/reducers/index.ts
@@ -26,6 +26,7 @@ import * as userReport from './userReport';
 import * as updateMentorData from './updateMentorData';
 import * as questions from './questions';
 import * as filterMentors from './filterMentors';
+import * as minimumVersion from './minimumVersion';
 
 import * as actions from '../actions';
 
@@ -72,6 +73,7 @@ export const rootReducer: automaton.Reducer<AppState, actions.Action> =
       markMessageSeen: markSeen.reducer,
       feedbackQuestions: questions.reducer,
       filterMentors: filterMentors.filterMentorsReducer,
+      minimumVersion: minimumVersion.reducer,
     }),
   );
 
@@ -96,4 +98,5 @@ export const initialState: AppState = {
   markMessageSeen: {},
   feedbackQuestions: questions.initialState,
   filterMentors: filterMentors.initialState,
+  minimumVersion: minimumVersion.initialState,
 };
diff --git a/src/state/reducers/minimumVersion.ts b/src/state/reducers/minimumVersion.ts
new file mode 100644
index 00000000..0e99a46f
--- /dev/null
+++ b/src/state/reducers/minimumVersion.ts
@@ -0,0 +1,77 @@
+import { Reducer } from 'redux-automaton';
+import * as RD from '@devexperts/remote-data-ts';
+import * as automaton from 'redux-automaton';
+import * as actions from '../actions';
+
+import * as minimumVersionApi from '../../api/minimumVersion';
+
+import { Action } from '../actions';
+import { AppState } from '../types';
+import { withToken } from './accessToken';
+
+import { pipe } from 'fp-ts/lib/function';
+
+export const initialState = RD.initial;
+
+export const reducer: Reducer<AppState['minimumVersion'], Action> = (
+  state = initialState,
+  action,
+) => {
+  switch (action.type) {
+    case 'minimumVersion/get/start': {
+      if (RD.isPending(state)) {
+        return state;
+      }
+
+      return automaton.loop(
+        RD.pending,
+        withToken(
+          minimumVersionApi.fetchVersions,
+          actions.make('minimumVersion/get/end'),
+        ),
+      );
+    }
+
+    case 'minimumVersion/get/end': {
+      return pipe(action.payload, RD.fromEither);
+    }
+
+    default: {
+      return state;
+    }
+  }
+};
+
+const isVersionBigEnough = (
+  clientVersion: minimumVersionApi.AppClient,
+  requiredVersion: minimumVersionApi.AppClient,
+) => {
+  if (clientVersion.major > requiredVersion.major) return true; // eslint-disable-next-line padding-line-between-statements
+  if (clientVersion.major < requiredVersion.major) return false;
+
+  // if major version equal, cmpare minor
+  if (clientVersion.minor > requiredVersion.minor) return true; // eslint-disable-next-line padding-line-between-statements
+  if (clientVersion.minor < requiredVersion.minor) return false;
+
+  // compare patch
+  return clientVersion.patch >= requiredVersion.patch;
+};
+
+// Default to true if no client found, or error in fetching
+export const selectIsVersionBigEnough =
+  (app: minimumVersionApi.AppClient) =>
+  ({ minimumVersion }: AppState) => {
+    return pipe(
+      minimumVersion,
+      RD.fold(
+        () => true, // NotAsked
+        () => true, // Loading
+        () => true, // Failure
+        clients => {
+          const foundClient = clients.find(p => p.client === app.client);
+
+          return foundClient ? isVersionBigEnough(app, foundClient) : true;
+        },
+      ),
+    );
+  };
diff --git a/src/state/types.ts b/src/state/types.ts
index 105b26a5..10073469 100644
--- a/src/state/types.ts
+++ b/src/state/types.ts
@@ -7,6 +7,7 @@ import * as buddyApi from '../api/buddies';
 import * as mentorsApi from '../api/mentors';
 import * as messageApi from '../api/messages';
 import * as feedbackApi from '../api/feedback';
+import * as minimumVersionApi from '../api/minimumVersion';
 import { PollingParams } from './reducers/messages';
 import { UpdateKey } from './reducers/updateMentorData';
 
@@ -75,4 +76,5 @@ export type AppState = {
     sendDeviceToken: RemoteAction;
   };
   feedbackQuestions: RemoteData<Array<feedbackApi.Question>>;
+  minimumVersion: RemoteData<Array<minimumVersionApi.AppClient>>;
 };