I've been using Ibotta now for a couple of years. It takes a few minutes before you go shopping to check off things or review updates on the app, but totally worth the small amount of time put into it. I catch myself sometimes buying something online, only to realize I didn't go through Ibotta! There's lots of businesses you can pick from to get money back, and very satisfying when you receive cash. There's a few glitches here and there, but it usually evens out.
If money is missing or missed, they are quick to answer and resolve it.