Every smart phone has video ability. Rather than write your testimony, filming your testimony is just as easy. Windows Movie Maker and other free video apps give you an inexpensive way to create a nice video that shares how God is working in your life. Be aware of copyright laws when sharing videos (i.e. sharing whole songs or copyrighted photos).
Here are some examples:
If you look into other false religions and cults, you will find them using this method. People follow what inspires them. They will not remember facts or statistics, but the message from a good story. An article from Perspectives.org says the world is becoming more of an oral learner and less literate. A video is a great way to tell the story of how you became a believer.