I am writing my own classes for a project. Apparently RubyMotion recognises some CocoaTouch classes but if I were to write my own classes, Sublime would not be aware of it. How do I rectify this?
Are you using Sublime for RubyMotion development as well? If so, are you using the RubyMotion completions? That could be why you're seeing CocoaTouch class completions.
Sublime doesn't have a built-in code intelligence engine, so if you write your own classes, it won't know about them.
That said, there are some packages that may provide what you're looking for: