Learn how to use Blynk with Node.js on a variety of platforms.
The control of a robot may be painful as you have to develop specific clients for each mobile device. I propose a Web based control
BBBmini is a state of the art Linux autopilot / flightcontroller Cape for the BeagleBone. It can be used for Copter, Planes or Rovers.
An experimental skill for using Amazon Alexa to control Bose SoundTouch speakers.
An Internet connected device that controls servos and sends sensor (GPS/gyro/accel/compass) updates in real time over a GSM cell link.