hmkcode/Android — reverse-engineered prompt

Build me a repository of small Android example apps in Java, like a tutorial collection someone can open and run one by one. I want each sample to focus on a common mobile task and keep the code easy to read, because this is mainly for learning and blog style examples.

Please include examples for things like making HTTP requests and getting JSON, posting JSON, checking connectivity, using SQLite, getting the current or last known location, opening the camera, custom views and simple canvas drawing, RecyclerView and custom ListView screens, navigation drawer, tabs and swipe views, options and action bar menus, starting activities, share intent send, material style sign in and profile style screens, and social sign in if practical.

Keep each example self contained, simple, and runnable on its own with a short note on what it demonstrates and how to launch it. If anything is outdated, use the closest current Android approach while keeping the spirit of the original examples. You can look up current docs online if needed.