diff --git a/KinEcosystem.podspec b/KinEcosystem.podspec
index 6b5bedc..4b82eec 100644
--- a/KinEcosystem.podspec
+++ b/KinEcosystem.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'KinEcosystem'
-  s.version          = '0.9.0'
+  s.version          = '0.9.1'
   s.summary          = 'Kin Ecosystem mobile sdk for iOS'
   s.description      = <<-DESC
 Kin ecosystem mobile sdk for iOS
@@ -11,7 +11,7 @@ Kin ecosystem mobile sdk for iOS
   s.author           = { 'Kin' => 'kin@kinfoundation.com' }
   s.source           = { :git => 'https://github.com/kinfoundation/kin-ecosystem-ios-sdk.git', :tag => s.version.to_s }
 
-  s.ios.deployment_target = '8.1'
+  s.ios.deployment_target = '9.0'
   s.resource_bundle = { "kinLocalization" => ["KinEcosystem/*.lproj/*.strings"] }
   s.source_files = 'KinEcosystem/**/*.{h,m,swift}'
   s.resources = 'KinEcosystem/**/*.{xcassets,xcdatamodeld,storyboard,xib,png,pdf,jpg,json,strings}'
diff --git a/KinEcosystem/Core/Kin.swift b/KinEcosystem/Core/Kin.swift
index 740a61a..6d329cc 100644
--- a/KinEcosystem/Core/Kin.swift
+++ b/KinEcosystem/Core/Kin.swift
@@ -13,7 +13,7 @@ import StellarErrors
 import KinUtil
 import KinMigrationModule
 
-let SDKVersion = "0.9.0"
+let SDKVersion = "0.9.1"
 
 public typealias KinUserStatsCallback = (UserStats?, Error?) -> ()
 public typealias KinLoginCallback = (Error?) -> ()
@@ -72,6 +72,9 @@ public class Kin {
     fileprivate var nativeOffersInc:Int32 = -1
     fileprivate var brManager:BRManager?
     
+    // a temporary workaround to StellarKit.TransactionError.txBAD_SEQ
+    fileprivate let purchaseQueue = OperationQueue()
+    
     public var lastKnownBalance: Balance? {
         return core?.blockchain.lastBalance ?? nil
     }
@@ -95,6 +98,16 @@ public class Kin {
         }
     }
     
+    init() {
+        purchaseQueue.maxConcurrentOperationCount = 1
+        NotificationCenter.default.addObserver(forName: UIApplication.didEnterBackgroundNotification, object: nil, queue: nil) { _ in
+            self.purchaseQueue.isSuspended = true
+        }
+        NotificationCenter.default.addObserver(forName: UIApplication.didBecomeActiveNotification, object: nil, queue: nil) { _ in
+            self.purchaseQueue.isSuspended = false
+        }
+    }
+    
     public func start(environment: Environment) throws {
         guard core == nil else {
             return
@@ -377,19 +390,31 @@ public class Kin {
             return false
         }
         defer {
-            _ = attemptEx(2, closure: { attemptNum -> Promise<String> in
-                return core.onboard()
-                    .then {
-                        Flows.nativeSpend(jwt: offerJWT, core: core)
+            // a temporary workaround to StellarKit.TransactionError.txBAD_SEQ
+            purchaseQueue.addOperation {
+                let group = DispatchGroup()
+                group.enter()
+                let attempt = attemptEx(2, closure: { attemptNum -> Promise<String> in
+                    return core.onboard()
+                        .then {
+                            Flows.nativeSpend(jwt: offerJWT, core: core)
+                    }
+                }) { error in
+                    self.recoverByMigratingIfNeeded(from: error)
+                    }.then { jwt in
+                        completion(jwt, nil)
+                    }.error { error in
+                        completion(nil, KinEcosystemError.transform(error))
                 }
-            }) { error in
-                self.recoverByMigratingIfNeeded(from: error)
-            }.then { jwt in
-                    completion(jwt, nil)
-            }.error { error in
-                    completion(nil, KinEcosystemError.transform(error))
+                
+                attempt.finally {
+                    group.leave()
+                }
+                
+                group.wait()
             }
             
+            
         }
         return true
     }