This app is fine as far as testing the state names, locations, and capitals. It is not especially well-designed. For instance, the mute button does not actually mute the sounds in the app, which is especially irritating because it prevents other apps, e.g. the podcast app, from playing in the background.
It will be totally serviceable once the developers make some tweaks to improve the user experience, but I do expect better if I’m going to pay for an app.