Mobile App: AngularJS +Ionic Fr. + JS - how to catch drawing on screen

HELLO (here is a questions: how to make a comma and new line so the word "currently" is from small letter and in new paragraph? If I do this in a "normal way" after saving changes stackoverflow deletes the "hello" word :( ) Currently I am writing a mobile application - a chat (something like facebook's messenger - very very similar). And what I would like to do is provide a functionality which will allow user to "draw" by finger on the screen and send the drawing to the other user with whom he's chatting. It would be good to "convert" this to an image (like jpg) so both users can for example save the drawing to phone.

Can you please help with this and explain what should I do to achieve my goal?

Thank you