Microsoft Mobile (formerly Nokia) announced a new app called Video Tuner for Windows Phone 8.1 today that should be interesting for budding videographers: It lets you edit videos right on your handset, instead of downloading to your PC and editing from there, and do so with a powerful array of tools.
Video Tuner isn't the first video editor for Windows Phone, of course. But since it comes from Microsoft/Nokia, it's notable. More to the point, it actually looks pretty good, especially on a bigger-screen device, like the Lumia 1520 or Icon/930.
Speaking of notable, I'd point out that the user interface for this app is excellent but in no way bears any resemblance at all to the Windows Phone/Metro user experience guidelines. I'd be upset by this if it didn't look/work so well.
Anyway, Video Tuner provides a number of useful and powerful tools, including:
Video editing. You can trim, crop, rotate, flip, mirror, and change the speed of the video you're editing.
Color. You can change the exposure, contrast, and/or saturation of the video.
Filters. Video Tuner provides a wide range of filters, including several color filters (70s, warm and fuzzy, ocean, and so on), black and white filters (blues, greens, reds high contrast, more), black and white tone filters (antique, cream, cyan, etc.), and negative filters (black and white, and color).
Crop. You can crop the video by 1x1 (square), 16X9 and 9X16 aspect ratios or rotate the video.
Sound. You can adjust the volume, or add a music track and then adjust the volume of the music track and determine when it starts playing.
When you're done fiddling around with it, you can of course save your edited video and then share it normally using the many available methods in Windows Phone. Looks good.
Microsoft Mobile Video Tuner is available for free in the Windows Phone Store. Yes, it does require Windows Phone 8.1.