A painter (while he are painting) has two hands busy. Left hand he has a palette and another hand he has a paint-brush. He needs do notes and check marks on app. He can't use his hands. What I have: android, arduino, raspberry pi, electronics and B4X of course. How create a solution? Simple. Elegant... Cheap... For now I thought about two possibilities. voice. openCV (the paint-brush would be a virtual pen) Do you have another suggestions?