No frills  just good. I have my favourites that I keep going back to again and again. There are lots of puzzles for every ability  and no ads anywhere! It really is a bare-bones proposition. The help is a text file  and there are no hints. If you're stuck  you can always jump to the solution. That's not a hint  but it can help you determine techniques. I would be willing to contribute a couple dollars for this app.