Yup, we do text messaging. Yawwwn.
However, we also do Text-To-Speech, which will read out your message on your friend's phone, and Text-To-Wallpaper, which sets your friend's wallpaper to your text message.
This Hack sends your GPS coordinates to a friend, then automatically starts their navigation app to show them how to get to you.
Hack your friend's phone vibrator
Change your friend's background, or just send them a picture
Hack your friend's browser. To keep it safe, they will be prompted to open(or ignore) the website link.
What's their location, battery level, is their screen on or are they moving at the moment... all good questions that Hack can answer
Make your friend's phone fart, burp etc.
Make your friend's camera flashlight....uh....flash