One of the things that makes Checkout 51 superior to Ibotta is that you can buy the specified products at any store. With Ibotta, you are given a list of products, but can only buy them at certain stores for the rebates.
Ibotta finally wised up and is starting to offer rebates for particular products at any store. There are only a few this week, but I anticipate that number will be going up. Keep an eye out.