diff --git a/README.md b/README.md
index d7d8d48..edcf24d 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,30 @@
-### Swark
+# Swark
 
 SWiss ARmy Knife - Your everyday clojure toolbelt!
 
 https://clojars.org/org.clojars.stanv/swark
 
+## Basic usage
+
+### Clojure CLI/deps.edn
+
+Add this dependency to the :deps map in deps.edn
+`org.clojars.stanv/swark {:mvn/version "0.1.0"}`
+
+Require swark.core in your ns form:
+`(:require [swark.core :as swark])`
+
+Then you can use the Swark utility functions:
+`(swark/key-by :id [{:id 1 :name "one"} {:id 2 :name "two"}])`
+
+## Development
+
+Start a repl with `clojure -M:repl/reloaded`
+
+Create an uberjar with `clj -X:uberjar :jar swark-x.x.x.jar` (replacing x's with version)
+
+Install Swark locally with `clj -X:install`
+
+## License
+
 Swark by Stan Verberkt is marked with CC0 1.0 Universal 
diff --git a/deps.edn b/deps.edn
index 3f5401f..5a1d6ff 100644
--- a/deps.edn
+++ b/deps.edn
@@ -1,5 +1,22 @@
 {:aliases
- {:deploy
+ {:repl/reloaded
+  {:extra-deps {nrepl/nrepl                  {:mvn/version "1.0.0"}
+                cider/cider-nrepl            {:mvn/version "0.28.7"}
+                com.bhauman/rebel-readline   {:mvn/version "0.1.4"}
+                djblue/portal                {:mvn/version "0.34.2"}
+                org.clojure/tools.namespace  {:mvn/version "1.3.0"}
+                org.clojure/tools.deps.alpha {:git/url "https://github.com/clojure/tools.deps.alpha"
+                                              :git/sha "e4fb92eef724fa39e29b39cc2b1a850567d490dd"}
+                org.slf4j/slf4j-nop          {:mvn/version "2.0.5"}
+                lambdaisland/kaocha          {:mvn/version "1.71.1119"}
+                org.clojure/test.check       {:mvn/version "1.1.1"}
+                ring/ring-mock               {:mvn/version "0.4.0"}}
+   :main-opts  ["-m" "nrepl.cmdline"
+                "--middleware" "[cider.nrepl/cider-middleware]"
+                "--interactive"
+                "-f" "rebel-readline.main/-main"]}
+
+  :deploy
   {:extra-deps {slipset/deps-deploy {:mvn/version "0.2.2"}}
    :exec-fn    deps-deploy.deps-deploy/deploy
    :exec-args  {:installer      :remote
diff --git a/src/swark/core.cljc b/src/swark/core.cljc
index c20977a..d7a3a29 100644
--- a/src/swark/core.cljc
+++ b/src/swark/core.cljc
@@ -7,13 +7,15 @@
 ;; Regarding collections
 
 (defn key-by
-  "Returns a map with all items in collection `coll` keyed by the value returned by `(f item)`"
+  "Returns a map with all items in collection `coll` keyed by the value returned by `(f item)`
+  When `(f item)` returns a falsey value, it is NOT included in the resulting map."
   [f coll]
   (when coll
     (-> f ifn? assert)
     (-> coll coll? assert)
     (->> coll
          (map (juxt f identity))
+         (filter key)
          (into {}))))
 
 (comment
@@ -21,6 +23,7 @@
   (key-by nil [{:id 0 :name "ab"} {:id 1 :name "cd"}])
   (key-by :id nil)
   (key-by (partial reduce +) [[1 1] [1 2] [2 3 5] [3 5 8 13]])
+  (key-by :user/id [#:user{:id 12 :name "u12"} #:user{:id 23 :name "u23"} {:id 34 :name "not-included!"}])
   )
 
 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
diff --git a/uberjar.sh b/uberjar.sh
deleted file mode 100644
index dd70be1..0000000
--- a/uberjar.sh
+++ /dev/null
@@ -1,3 +0,0 @@
-#! /bin/bash
-
-clj -X:uberjar :jar swark-0.1.0.jar
\ No newline at end of file