Terrabook is an Android app developed by Mas Bram that serves as a small and simple offline wiki. The app has over 1200 items in total, which can be searched by category or all at once. It has a simple and focused UI design that is easy to navigate. One of its best features is that it is offline and does not require internet permission.

Another feature of Terrabook is the ability to mark items as favorites, making it easy to find them again later. The app is completely free and has no ads, making it an excellent choice for anyone who wants to learn something new without any distractions.

Overall, Terrabook is an excellent app for anyone who wants a simple and straightforward way to access information without having to worry about internet connectivity. With more items coming soon, it's only going to get better.