Strum is a brand new app from Smule Inc, it allows you to transform simple videos into filtered films with vignettes, viral vids or holiday greetings. There are also advanced audio filters that automatically compose music to match your video and there are over 20 different visual and audio styles from simple background melodies to outrageous remixes. It comes from the Smule stable and is free and also comes with a free Stone filter for a limited time (that’s a saving of $2.99/£1.99). Click here to give it a try.