Microsoft Video Tuner App Lets You Edit Videos On The Fly From Your Lumia Smartphone
You won't find the same controls as full featured (and awfully expensive) video editing programs offer, but Video Tuner is free and offers some neat tools. For example, you can trim, crop, rotate, flip, mirror, and change the speed of your video as you're watching it.
"Delve deeper and you'll find more advanced features, such as adding music to your video and adjusting the volume to suit particular scenes," Nokia says.
In case you're wondering, the answer is yes, there are filters to play with as well, just as you've grown accustomed to in the myriad photo apps like Instagram. Granted, even with those coveted filters this might not be the end-all-be-all of video editing, but it's certainly an interesting and convenient step in the right direction on mobile devices, and it's free. It's also exclusive to Windows Phone 8.1 (Microsoft developed the app).
If you want to fool around with it, you can grab Video Tuner from the Windows Phone Store.