title: Android/iOS - How to build an app which will be called only when you want to attach an image?
body: <p>Firstly I am not a native english speaker so I had trouble to find how to explain my issue. Please apologize.</p>
  
  <p>So I want to build an app which will be called only when you want to attach an image to a message (text, mail, etc..). Like the gallery or camera app.</p>
  
  <p>The user will choose a specific content in my app then I will return the selection to the app which called mine.</p>
  
  <p>Is that possible to do that ? I am looking for the answer on both platform: iOS/Android. (Edit: I have skills in both Java and Objective-c programming).</p>
  
  <p>Thanks :)</p>