Control Pad with Bluetooth Connectivity to Android Tablet

I want to build a simple control pad with a central dial and 3 buttons each of which performs actions / output to an android tablet.
I’ve designed an android App which simplifies making a video call for my Mum (she’s unable to use a touchscreen and isn’t good with tech!)
Now I need to build a control pad with a dial to select who to call and 3 buttons - one to select/make call, one to go back/hang up call and one to take her to a home screen).
If anyone in the community can point me in the right direction to find someone to make the board / program it I’d be very grateful as the physical controls side of things is all new to me.