It’s Backbone One controller. Works out of the box (including pass-through charging and USB audio), but some applications don’t detect buttons correctly, so I remapped them using xboxdrv.

Yes, it’s the official Pine keyboard. But it’s only for PinePhone(Pro). It a replaces back cover with a clamshell and uses pogo pins on the back for connection. The keyboard also have additional battery. I think that the keyboard makes it a bit heavy, but the phone discharges too fast without it (RK3399S is very hungry!) and the virtual keyboard on Linux is not as good as on Android. So it’s a must have accessory.