I just tried it out and it seems to work as a simple introduction though for some reason the STL file it said it emailed to me hasn't shown up yet. I don't really use the iPad email much so can't say if it's an iPad problem or something with this app. The set of basic shapes you can use include simple things like sphere and box but many are greyed out (meaning I guess that they are available for purchase). You can also place letters though every letter after C is greyed out. For this reason, this appears to be more of a demo than a usable app in its totally free state.

Perhaps the objects are cheap. I didn't check. The reason is that I just used Tinkercad before this and was able to have a simple idea, save it as an an STL and view it in Meshlab in a couple minutes.

If anyone has other questions, I can load it up and check but for now I'm going to learn how to better use Tinkercad. (Got a Makerfarm i3v, my first printer, coming in a week or so .