So you want to put your latest action camera footage on Instagram or Vine, but you'd rather not transfer the entire video to your computer or phone just to produce a seconds-long highlight. What to do? As of today, GoPro has an easy answer. It's rolling out a trimming feature that produces short, share-worthy clips, whether you're editing in the mobile app or on the camera itself -- you could post a video of your mountain bike adventures while you're still taking a breather. You'll need a full-size Hero4 to trim on-camera, but the Hero4 Session and any other WiFi-capable GoPro cam will play nicely with app-based trimming.