One of the biggest hits in iOS games right now is Bridge Constructor, made by Headup Games in Germany. Available as an iOS, Steam, Android or Windows Phone app, Bridge Constructor is a game in which the player must design and build a bridge that meets specific criteria and that can withstand the tests the app throws at it.
Relying heavily on physics as well as the basic criteria of the various materials available for building the bridges, the app drives vehicles over them and tests your design. Your creation will either stand proud or crumble.
As you progress through each level, the challenges get tougher and tougher. The gaps get wider, the terrain rougher, the obstacles more in the way, etc. You must conduct stress tests to check your work before “going live” and allowing traffic on your bridge.
More than that, though, you must stay within a construction budget as you design and build, which will affect your materials choice and your design options. In fact, the budget you’re given is basically the only limit you have, though some of the early levels don’t have all of the materials available either – helping you to learn each of the options as you progress.
This is definitely a great game and one that I’ve had a good time playing. Be warned that it’s addicting, however, and you will likely be buying add-ons for it to feed that monkey.