I've written quite a few posts about the game of Nim, but practice is the real key.

In this post, we'll take a look at iOS Nim apps that you can download and use to practice for free on the go! Yes, there are free Nim apps for Android devices, but the variety is a little wider for iOS devices.

Most of the Nim apps you find are based on either single-pile Nim or multi-pile Nim.

For single-pile nim, try out Take Apples and NeonNim: The Subtraction Game. Multi-pile Nim can be practiced with the Stick Showdown and myQuickGame Free apps. If you want to switch between the two, there's the simply-named Nim Game and the aptly-named Appointed Win Game.

Back in June 2010, Scam School featured an episode of Nim without props. You'd wouldn't think you could turn a propless Nim game into an app, but it has been done! The calendar Nim variation is available as The Date Game. The other version is available as Race To 100.

There's also the ingenious tic-tac-toe variation of Nim known as Notakto. Notakto's winning approach isn't as easily picked up as some of the other variations of Nim. However, you can learn via my tutorials over in the Mental Gym, How to Play and Win Notakto and How To Play and Win Notakto: 3+ Boards.

There are a few variations of Nim out there, however, for which there are few (if any) ready-made tutorials. If you're up for the challenge, try a version with unfamiliar rules and strategies, and see how well you can do at working them out yourself. There's TacTix, in which you remove items from any contiguous columns OR rows, or the similar Triangular Nim, which throws diagonals into the mix, as well!

Probably the most challenging version of Nim is Hakenbush, which involves erasing lines, and eliminating any lines which are no longer connected to the base. Since there are endless possible shapes and color combinations to use, working out a general strategy is tougher than it may first appear!

I hope you find these versions of Nim fun and thought-provoking. If you have a favorite free Nim app, for any device, let me know about it in the comments!