We all love the Blink Example of Arduino. Almost everyone uses this example as their first code. What if we could Blink the LED using over internet using our phone from anywhere in the world.
This is the simplest project you are ever likely to come across. It uses Blynk app which is available for android as well as IOS. The app connects your hardware to the cloud and controls your project over the internet. It's pretty cool for monitoring things.
I have connected a led to the Arduino and created a project on the app. AS soon as the system is online you can control your led from your phone.
Happy Hacking :)