I found Gomagic from the YouTube channel of the same name. It’s a really nice way to do high to mid-kyu Go problems (there’s a 9k - 1k section under development too). They have a wide variety of types and it walks you through a bunch of different skills.

The downside is you only get a limited number of free problem sets each day if you don’t pay for a subscription, but it’s like 15 free sets of 5-6 problems per day or something pretty generous.