Make your smartphone with Raspberry Pi A+
Touchscreen Internet Radio that can be controlled with PC, Smartphone
Monitor Arduino Sensor using Smartphone and ESB: IoT Tutorial
Get connected to your Raspberry with just the help of your smartphone.
A Raspberry Pi powered photobooth controlled via your smartphone.
Wake-up Light connected to smartphone
Lock away your tempting smartphone for a few minutes or hours
Use RGB LEDs and a Bluetooth-capable Arduino