Word comes via ChessToday that Judit Polgar has an app for beginners that is newly available (more about this here and here). While readers of this blog might be interested for the sake of gifting it to others, I doubt that many of you are at the stage where it might still do you some good. But what apps, if any, have you used with benefit? In my limited experience chess apps are still pretty disappointing, in that you can find one that does this and one that does that, but none that can do this other thing or that even put this and that together.
For instance: there are apps with strong engines like Stockfish, and apps that are decent as PGN readers (e.g. Everyman's e-reader). But a strong engine/quality PGN reader combo? Not the last time I checked, but to be fair it has been a while. (This is where you come in, to relieve me of my woeful ignorance!) And I've been a waiting a long time for an app that will let you save variations in analysis and not just main lines, but so far it's a no-go. There is a rumor that ChessBase has one in the works, but as far as I know it's not out yet.
One app I've used off and on and find useful is the Tactics Trainer app. It has a pretty large stock of puzzles, chosen at random (but within certain rating ranges - a 2000 won't get puzzles suitable for 1000-rated players, and vice-versa), and is appropriately frustrating when you lose concentration. If you use your iPad or iPod/iPhone frequently for entertainment purposes, it might be just the tool for you to practice your tactics.
But now to you, dear readers. What apps (Apple or Google or whatever else) are you familiar with and able to recommend?