The music industry might not be as strong as it was in the 80s, but there are still plenty of ways to make money online as a musician. Sites like SoundBetter let you sell your services as a songwriter, producer, or session musician to thousands of customers a month. While Musicbed, Music Vine, Marmoset, and SongFreedom are perfect for licensing your music to TV shows, movies, and web series.
There are also shopping apps like ibotta, MobiSave, and checkout 21 that give you money back for shopping. And the Walmart app has a savings catcher feature where you take a picture of the barcode or upc at the bottom of your receipt and they search all surrounding store and if a lower price is found they give you the difference back. I have made about 50 bucks total from this app and 20-30 from things like ibotta.