To create a custom control setup, just make sure to correctly sync your peripheral devices, and pick a game. After that, you can start mapping the controls by linking areas on the screen to buttons or keys on your peripheral device. Octopus even makes it possible to a mouse, which is great for shooting games like PUBG Mobile or Rules of Survival. On top of all that, you can also adjust the opacity of the controls when shown on the screen, and make them nearly invisible so they're not distracting during games.
Octopus also has a trending tab, where you can take a look at currently popular games and even check exactly how many people are using Octopus to play each game. For example, Free Fire is usually the most played game, because once the controls are mapped, playing this title a keyboard and mouse is simply awesome.
Overall, Octopus is a great app for Android gamers, that makes it possible to play almost any game with a keyboard or gamepad. Depending on the game, Octopus can give you a significant edge over players using touch controls.