Android: Create your own sharing app
One of the first applications I did for Android was a very simple
application which simply takes a picture using Camera and then send it
to a remote server.
Very simple, but it introduced to me into the android world and the notion of activities and communication between different applications.
A little addition to this application I wanted to make was the possibility to share any of the pictures already taken.
To do that I wanted to add the application to the list of the choices which appear when an user click on the "share" button when view an image using the default Gallery application.
Nothing easier than that! It was just a matter of a couple of tags to
be added to the AndroidManifest.xml and the trick was done!