A free app for Android, by WANUA_Dev.

Like a textbook, this app offers everything you need to know about Java programming. Java Programming – Documentation contains a wide variety of topics including data types, object-oriented programming, and more. It features a bookmark option so you can access your favorite content during your free time. The search option, on the other hand, is useful when you need to look up a topic. 

The interface is user-friendly, which means you don’t have to spend too much time navigating the features of the app. Java Programming – Documentation is perfect for budding programmers as well as those who need a refresher course on Java programming.