Android P will allow to use your phone as a Bluetooth Keyboard or Mouse
Android P, the next major release of Android Oreo, which Google calls Pistachio, will release a developer preview in the coming weeks. According to the latest from XDA Developers new, the Android P system allows users to use their phone as a wireless keyboard and wireless mouse over Bluetooth.
“Bluetooth-enabled devices can offer support for what are called “Bluetooth Profiles.” You might be familiar with some of the more common ones, such as the Hands-Free Profile (HFP) and Advanced Audio Distribution Profile (A2DP), which are typically used for voice calls and music streaming respectively. Implementing the Human Interface Device (HID) Bluetooth profile allows for input devices such as mice, keyboard, joysticks, and more to work.
By default, Android (as in, the base build from the Android Open Source Project) does not implement support for HIDD in the Bluetooth stack. That means app developers cannot create apps utilizing the service to enable your smartphone to be used as a basic keyboard/mouse input device. There are root-enabled apps on the Play Store such as Bluetooth+ which patch the Bluetooth framework to enable HIDD, and when combined with another app such as True Mouse/KB, you can use your smartphone as an input device.”