Star Rate Images is a simple app for adding Windows-compatible ratings to images. Many photo gallery apps let you favorite/rate images, but once you copy your files over to your computer, your ratings are lost, because the files themselves weren't updated with the rating, it was just recorded in the app.

To use:
Click "Select Images" and then select one or more files (press and hold to select multiple). Select a rating and click Apply.
On your computer, in eg Explorer, you can add a column to display each file's rating.

I've open-sourced this project in the hopes that popular gallery apps will implement this feature.
https://github.com/kurupted/Star-Rate-Images

Features:

Select JPEG images from the device, OR, Share images from a gallery app to Star Rate Images.
View the list of selected images along with their current ratings.
Apply a star rating to selected images.
Saves ratings directly into the images' metadata.

This currently supports jpeg files only. I'd like to add mp4 support but unsure how at the moment.