So you would like to build your own robots? The Keigan Motor can help. It is a Bluetooth brushless and gearless electric motor that brings your robots to life. You can use multiple motors to work simultaneously together to perform complex tasks. You also get position and speed control and can run these on battery.
Keigan Motor has a control board with a motor driver, rotary coder, flash memory, 6-axis accelerometer-gyro, and everything you need to get started. iOS and Android devices are supported.