HTML is a diaplay languge, not a programming language, so you can't write apps in it.
The best way is to learn to write apps (it's called programming), then learn Java, then learn the Android environment, then write your app, on paper, in English. (It needs a class to do this, a class to do that, etc. Then write each class. Then connect the classes with the main app, depending on what the user is doing.)
Then translate what you have into Java, using the SDK.
That's how all computer programs that are actually written (as opposed to using an "app writing app", modifying an existing app or drag&drop design, none of which create apps that people actually find useful) are written. You have to know how to write a program, you have to know the language you're going to use, you have to know the environment it's going to run in - then you write it.
If you're thinking of releasing a good drawing app by the end of the summer, don't get discouraged when you don't. You can possibly learn the basics of programming by that time. Not enough to write a drawing app, but the basics. The good apps you see in the Play store represent at least a few years of programming experience. (The ones you try and find that they don't work, they don't really do much or they aren't very useful, are the ones written by people who think they can learn to write an app in a week or so.)