Great concept. First, it's not free, $2.99. I like devs to be upfront with this. I like the concept. Works well with my way of learning. Usually when I memorise stuff without context I forget it very quickly, so I always have to create a little story around what I am learning. With this app, I don't have to do that. It's not always obvious to me some of their ideas, but it works. I noticed that some of the same characters appear in different levels. Fix pls. Need option to turn off sound effects.
Hidden costs. It costs £2. I would have bought it if you'd be upfront.