It lets you practice specific scenarios like soft hands or hands with unintuitive correct moves (e.g. 9/9 vs 7, stand). I’m working on adding analytics for things like which hands the user gets wrong most often.
If you're curious, the charts are all based on ones from Wizard of Odds. Also, it simulates a shoe behind the scenes so you can practice card counting (not randomized each hand).
There's no mobile support yet but I plan to add it if people find it useful.