SmartBoy Companion is a free Android utility and tool application developed by Hyperkin that allows you to play your favorite Game Boy and Game Boy Color cartridges on your smartphone. This app supports both the Development Kit and Retail SmartBoy Type-C versions, but the latter is required for all features.

With SmartBoy Companion, you can easily plug in your Game Boy or Game Boy Color cartridge and start playing right away. The app offers a seamless gaming experience with no additional setup required. It also allows you to save and load your game progress, making it easier to pick up where you left off.

In addition, SmartBoy Companion supports a variety of different controller options, including Bluetooth controllers and the SmartBoy Type-C controller. This means you can customize your gaming experience and find the control scheme that works best for you.

Overall, SmartBoy Companion is a fantastic tool for anyone looking to relive their favorite childhood games on their smartphone. With support for both the Development Kit and Retail SmartBoy Type-C versions, it's a versatile and accessible app that's definitely worth checking out.