I'm working on a project in which I want to add a draw/sketch feature that draws by the user's touches on screen. That way they can make simple drawings on a view. This is a concept used in many picture apps (i.e. SnapChat). I've done many Google searches but haven't found anything out there that I could use. Does Apple have a guide or class for this or is there are any algorithms or code out there that's available to the public? Please provide me with references or information regarding this topic. Thanks in advance for your time.
I really like the ray wenderlich tutorials. They also have a tutorial on how to make a simple drawing app.
http://www.raywenderlich.com/18840/
I think it should give you a hint on how drawing works.