This app allows you to upload photos that you've already sorted straight into multiple albums in your Google Photos account. This way you don't need to sort them again once they've been uploaded, or manually upload individual albums. The app keeps track of which items you've already uploaded so when you run it again it will only upload the new items.

Simple choose the folder that contains your albums (sorted into folders), and let the app do the rest.

For free, you can upload 50 albums with up to 250 items per album (which should be plenty for most users), and you can remove this limit for a small fee.