Joy-Con Droid is an app that turns your Android into one of the controllers of the Nintendo Switch system. You can choose between the two Joy-Con (left or right) or even the Pro-Controller. You can also connect a USB controller to your device to control the console.
It's important to note that to use and set up Joy-Con Droid you need at least an Android 9.0 smartphone and to have Bluetooth HID Profile. If your smartphone doesn't meet those requirements, it's very possible you'll get different error messages.
The first thing you'll see when you enter Joy-Con Droid for the first time is a complete tutorial that explains, step by step, how to set up your Android as a Joy-Con. Once you've watched the tutorial, you can start setting up the app as you please. You can 'map' the buttons however you want, activate or deactivate the motion sensor, and even change the colors of the interface.
Joy-Con Droid is a very useful app, especially for those who have a Nintendo Switch and want to play with friends but don't have a bunch of extra controllers lying around the house.
