When I looked for a free tool to practice blackjack, I wasn't really able to find one that had the configurations and polish that I was looking for.
So I made this completely free trainer that teaches you when you make mistakes and also lets you see a heatmap of the errors you made. For advanced players I'd recommend enabling count based deviations.
https://www.blackjacktrainer.fyi/
Feel free to try it out and let me know what you think!
