This app is a Godsend for anyone who has Android 10 on their device and is still using old legacy apps that have options/settings menus that can only be accessed via the hardware Menu Button, which Google removed the API for on Android 10. Ken Magic Solitaire is an example of this kind of app. There are two less-than-perfect aspects to Menu Button: 1. The button can't be docked with the other buttons on the Navigation Bar, it floats on the main window. 2. The app uses a custom keyboard, which you have to switch too when using the custom buttons. But this is a small price to pay when the alternative is to abandon an app you like, just because Google removed a component that it required. The app can emulate 31 different buttons, not just the Menu button: volume controls, copy/paste, screen lock, and several typing cursor controls. It displays small, relatively unobtrusive ads in the configuration screen when an active internet connection is present.