What APIs are used to draw over other apps (like Facebook's Chat Heads)?

Question

How does Facebook create the Chat Heads on Android? What is the API to create the floating views on top of all other views?

Answer 1

Springy heads gives spring based behaviour of chat heads out of the box. All you have to define is the drawable for the chat head and the fragment to open once the chat head is clicked. The chat heads collapse when minimized and follow the finger when dragged.

The project includes a demo app which demonstrates all the built in functionality. To use it, you need to add this into your gradle dependencies.

compile 'com.flipkart.springyheads:library:0.9.6'