You just need to download it on Google Play search for (Bitstrips) it is around 49mb. It is a very simple app, don't need to be a scientist just to figure out how to use it.
Just a brief info maybe, you first got to create your avatar then find your friends and add them. Create a comic strip using a ready made templates and just edit the caption or text. Once you are done with it you can share via Facebook or to any I.M such as WhatsApp:
As you can see, you can edit the text and even make your friend avatar first if they have not join yet and maybe they can select it directly after being invited by you I think. Below are some of the comic strip created by me:
Share instant comic messages starring you and your friends.
• Design cartoon versions of yourself & your friends
• Put your friends in hilarious comics where anything can happen
• Show how you’re feeling with cartoon status updates
• Choose from 1000+ customizable templates, plus new ones daily