How to make game crossword puzzles with a backtracking algorithm?
What your asking requires good knowledge about Java and C++. For that, there are extensive tutorials you can use. You should download Android SDK on your computer to have base to start from and an IDE to work on.
I'd recommend CppDroid - new C/C++ IDE on Android. It has a lot of included C/C++ examples and tutorials. Blog: http://cppdroid.blogspot.com, Google Play: https://play.google.com/store/apps/details?id=name.antonsmirnov.android.cppdroid