Really fun!!! by Li3303

A great game! Copy the color pattern in the sample circle by turning the rings. There's one black empty space. You push the arc you want to move onto into the empty space then turn the rings to reposition it. It's like one of those number 15 puzzle games only with a circle, arcs and pretty colors.

Great game by XterryX

"Really a great game I didn't think it was hard enough but I was wrong. After the first puzzle it started to drive me nuts I LOVE this game."

Worth it by COB Masters

This app is absolutely amazing. It has intuative controls and runs smoothly. Worth 3 dollars and is the best fractal app out there.

Unsurpassed by UERD

This is by far the best calculator (if you can call it that) app on the iTunes app store (as of the beginning of 2009)- it has a featureset comparable to that of an advanced graphing calculator, like a TI-89, but with the benefit of a touch-screen interface and full-color graphics (which are especially nice for 3D plotting). SpaceTime also performs both numeric and symbolic algebra and calculus (including some advanced functions) and supports scripting. If you've used software like Maple or Mathematica, SpaceTime works in a similar function- not quite as feature-rich, but far more than you might expect from a handheld device.

Simply the best calc app for the iphone by ilachina

I used to own a Pocket PC (before it was stolen and I moved to an iPhone). I regretted nothing about moving to an iPhone except having to give up my one truly indispensible application on the PocketPC, namely SpaceTime. I lamented its absence from the iPhone ever since. Now its here and available! It is a programming tour-de-force, and really does provide a substantial subset of the functionality of desktop powerhouses like Mathematica and Maple. To compare it to a "calculator" is somewhat like comparing a racing car to a road bike. Vastly different leagues. It would arguably be worth the "price of admission" if all it offered was its graphing capabilities and nothing else. That it offers everything a conventional scientific calculator does plus a full suite of symbolic algebra functionality is a rich frosting on the cake. I applaud the programming team for developing an extraordinary little program, and for making it available to a broader community. It matches or exceeeds an HP-50g or Ti-89 for pure functionality, yet is offered for a fraction of the cost. If you are an engineer or scientist, or anyone in search of a full function scientific calculator/plotter/symbolic manipulator, you've found your iPhone dream app.

Wow! by aurorae_borealis

I am so lucky to find this application! I will never use TI-89 again! And the price is anbelievable! And you can do scripts! TI-89 costs over 100 dollars. You can use this application instead! Too bad our professor doesn't let us use phones on test. I will try to convince him by showing this application. SpaceTime is well worth the money.

Dump your graphing calculator! by Syldaril

This is truly an amazing piece of software for the iPhone that could potentially render all the graphing calculators out-there obsolete! I was very impressed with all the graphing features (2D, 3D, 4D, etc) and the powerful CAS loaded with preprogrammed funtions. SpaceTime solves and displays complex expressions in a fashion that reminds me of my TI 92's 'pretty print' mode. I highly recommend this application to every college student and math enthusiast!

Father of 10 and 6 by RamkiHome

Easy way to entertain and challenge the kids and some times helps the adults to focus and regain some attention span. Simple and cool interface. I had this in my windows mobile and glad they have it in iPhone.

Awesome! by llikeadodachacha

Does just about everything my TI-84 Plus but quicker and much easier to manipulate the graphs. It loads instantly and the 3D function is awesome for higher level math classes (I'm in Calc 3 now and it's already come in hand!)

Nice graphics, usability problems fixed! by RNMartin

My initial review pointed out difficulty editing equations without the standard iPhone keyboard, and the challenge of animating without more control over the variable T. These complaints were addressed with amazing speed, by the recent update, and I can say that the equation editing works smoothly, with a nice compromise between their custom keypad for quick entry, and the iPhone keyboard for more elaborate editing. The options for controlling the range and end behavior of the animation are complete but easy. I'm glad I bought this app even with several other graphing calculators already on my iPhone.