After developing the iPhone version of Werner Miller's Age Square, I became interested in what other iPhone programs were out there that would interest Grey Matters readers.

Before I go into other programs, I should mention that I've updated the Age Square iPhone webapp. First, if you tried it when I originally posted it, you may have noticed the graphics were somewhat slow. In the newer version, the graphics load up much faster. Another change is that you will get different magic squares each time. Yes, they will contain the same numbers and still give the same total, but there are now different arrangements that show up.

Finally, I've added a feature to the program that allows you to show off the patterns. Once the final age magic square is up, each time you tap anywhere in the top 2 rows, a new pattern of 4 squares that give the magic total will be highlighted. You can go through up to 24 different patterns before it clears the board. If you don't want to go through all 24, you can tap anywhere in the bottom 2 rows to immediately jump to the blank squares to restart.

Many of you are familiar with my iPhone Mental Gym, but for a long time, the Knight's Tour on there was a minor rewrite of my original Knight's Tour program. Having some iPhone programming under my belt, I figured this was my next project. The result is the completely new iPhone Knight's Tour. Right away, you'll notice it has been fully rewritten to better bring in line with iPhone standards. The board and the controls have been made larger and easier to use. There are a couple of brand new features, as well, including the ability to undo your moves (all the way back to the beginning!), the ability to end the game at any time, and even a feature that detects when you're trapped. If you do become trapped, you're offered the choice of undoing your last move or ending the game.

Other developers have been just as busy, and I've found a several webapps you can use to help strain your brain and entertain. Don't have an iPhone or iPod Touch? Don't worry, these will all work in your browser, as well.

Since I was just discussing the Knight's Tour, how about another chess challenge? Playing chess blindfolded has always been a challenge, but now there's the Blind Chess Trainer. This is a series of quizzes that will progressively help you understand how to think of the chess pieces, the board arrangement, and the movements, without ever seeing the board.

For those who do the Day of the Week For Any Date feat, you can now have the iPhone running this 200-year calendar (1900-2099) to help prove you're correct! For those who do the date feat, one especially nice thing about this calendar is that, if you follow the order of choices in this webapp for you presentation, all the hard work is done at the beginning. If you start by asking for the year, you have time to figure the year key, the century adjustment (if needed), and be aware of possible leap year adjustments, while they go through the selection of the century, decade, and year. Next, ask for a month and day, and you can add in their keys and cast out 7s while they go through the month and day menus. If you've practiced enough, you should be able to get the date almost as quick as they can find it using this calendar.

If you would like help memorizing any of these, don't forget iFlipr, a custom flashcard program for the iPhone that I recently mentioned. If you need to practice any memory technique, or memorize anything else, this is a great way to do so on the go.

Speaking of things previously mentioned on this blog, there's also the book Geek Logik, by Garth Sundem, who specializes in creating equations to help solve every day dilemmas, as mentioned in my review. For pure fun, there is now a Geek Logik webapp. It features several questions from the book, and allows to enter the needed variables to answer them, with full explanations for what each variable means. When you're done, you click the Calculate button, and (after a brief ad) you're given the answer.

Finishing up with another webapp for pure fun, try iPhone Magix. There are numerous iPhone webapps used for magic effects, but few of them are deceptive. However, iPhone Magix is one of the best iPhone magic routines out there, and it is truly deceptive. You can even repeat this routine, and it will become even more puzzling (as the method isn't always exactly the same).

Since we've started with a magic webapp, and finished with a magic webapp, I'd say we've come full circle. Let me know if you find any more ingenious iPhone programs (preferably ones that also run on browsers) that you think other Grey Matters readers would enjoy in the comments.