We need to trigger external effects (eg on a USB-attached embedded device) and sometimes do stuff like forget a BLE device in system settings. We‘ve been looking into making a fake mouse that can achieve the latter. If you can support both use cases, you‘ve won.

> fake mouse

That's what I'm doing with my new project, Valet. It's a Raspberry Pi configured to be a fake mouse, keyboard, and an Android (touch stylus). Works well on iOS and Android.