Photo effects applications are fairly common on most platforms, but this one's pretty well done. Tapershot (or Tapershop in the Store description, confusingly!) UWP has a vast array of effects and filters, many fully configurable, outputs at full resolution, and works on any Windows 10 phone, tablet or desktop.
With Tapershop, apply professional and nice effects, filters to your photos. Pick a photo on your device or take a photo from your camera, tap on filters (more than 80 available) and give your shots some improvements!
Apply filters and effects
Import a photo from your device or camera
Save as PNG, JPG, GIF, TIFF, BMP
Display a default photos folder
Crop and save
Set as wallpaper
Set as lock screen
I gave it a whirl on my Lumia 950 XL:
File and sharing controls at the top, editing controls at the bottom. Just pick a photo and then get fiddling. The Settings control brings up different sliders, depending on which editing function or filter is selected.
The range of adjustments, filters and effects is enormous, with the filter control bottom right letting you switch between banks/categories...
A wide range of formats to save to, though JPG is best and safest, of course, in terms of quality/size; (right) confirmation in Photos that the processed images are at full resolution (in this case, 8MP)...
With just a few UI bugs here and there (cough, portrait photos) and some updates needed, this is a great new little UWP application. There's an in-app-purchase, but it's only to buy the developer a coffee to say thanks. So, please do that, at least.