Even in the ideal setting, it's nearly impossible to get the perfect piece of footage that won't require edits. Those changes can be tough to tackle on mobile, but thanks to a YouTube update, perfecting a short video just got easier. Inside the video library's mobile app, a new video trimming feature let's you slide to the exact frame you want the video to begin (and end) before getting rid of the excess. There's also an inline preview, so you can do one last check before uploading to the web. If you're into capturing footage with your phone, these new tools should help you nix the "are you rolling" chatter before your pal's next stunt.