Most darts apps are scorers. You throw, you tap, they do the subtraction. That is genuinely useful and I used them plenty, but an auto-scorer is a cheat code for the exact skill you are trying to build. It takes the arithmetic away instead of teaching it, and it says nothing about the bit that actually decides games.
Which treble. Which setup dart. Which double you leave yourself, and where you end up when you miss it, which you will.
Dartistry teaches that. It is a coach and a practice partner, not a scorer and not a throw tracker.
It is honest about who you are.
Every checkout is priced in the only currency that matters: the average number of darts it takes you to get out, at your level rather than a television professional's. "Just hit the treble twenty" is bad advice for most players, and the app knows it. What it tells a new player and what it tells a good one are different answers, on purpose.
You get told why.
Pick a route in Route Quiz and you get a coaching note explaining the choice. Not just that it was right, but what your likely miss leaves you on and which double the road ends at.
Try the 84 checkout guide for a worked example: the route to the finish, what a single 20 leaves you, and how to recover.
Route Quiz
Pick your route, then find out why it was right or wrong, and where the miss would have left you.
The Leave
Two first darts and one question. What do you do with the third.
Coached 501
A real leg against a practice partner you build yourself.
Your data stays on your phone, because a darts app has no business knowing anything about you.
Android today. iOS is next in the queue.
If you have got something in a drawer, that is the bit I would take from this. Go and have another look at it.
Dartistry, a strategy coach for 501 darts.
It teaches the decision underneath the throw: which treble, which setup dart, which dou what a likely miss leaves you on. Priced at your level, not a professional's.