John GBC is a full version GB/GBC emulator for Android 4.1 and higher. It is important to note that the application doesn't work without importing your own game files. Before purchasing the app, it is recommended to try John GBC Lite. However, John GBC can take over John GBC Lite data. The app is not being actively updated, as John GBAC, the successor app, has been released.

One of the most attractive features of John GBC is its original GBC engine, which provides high-quality rendering and fast performance. The on-screen virtual keypad is customizable, and the app also supports Bluetooth/MOGA controller. The app also supports cheats (Game Genie/Game Shark/PAR), save states with previews, and Dropbox support (requires John DataSync). The app has no ads and does not require an internet connection. Additionally, it supports zipped files, screenshot, and super Gameboy borders. The fast forward/slow down feature (x0.25 - x16) is also a great addition for gamers who want to play games in their own preferred pace.

Overall, John GBC is a reliable and high-quality emulator that provides a great gaming experience for GBC enthusiasts.