Just download the free app called Fortunate on a friend's phone:
https://play.google.com/store/apps/details?id=com.fortunate
A one-time create an account screen will appear when the app is first opened. The account is used to identify what device to send the video to, so just type in something quick and memorable. It doesn't have to be an e-mail address.
Then you can go to this website:
http://fortunate.parseapp.com/
and schedule a video to pop up on a friend's phone. So you could send a Rick Roll, Archer or Jurassic Park virus video or even an embarrassing inside joke video that you upload yourself. Please keep things fun and friendly.
Enjoy!