Today's Free App of the Day is SimplePhysics
This is a golden oldie Free App of the Day. I picked it up in September 2012. I love these kinds of games. You need to build things. You have a test dummy that you can use, too.
From the product page:
The sequel to BridgeBasher is finally here! SimplePhysics lets you design complex structures for everything from tree houses to ferris wheels and then simulates your design with a sophisticated physics engine.
A wise person once said: "An engineer is someone who can do for a dime what any fool can do for a dollar." In SimplePhysics, your design must not only be strong enough, it must be cheap enough to win. With the built-in Leaderboards, you can also compete with people all around the world to see who can create the most cost effective designs.
Create your design in seconds with the blueprints editor. If you make a mistake, simply tap the Undo button. Zoom in and out by pinching the screen and pan the view using a two finger drag.
While testing, you can see how the strain is distributed across your design. Areas that are under immense strain are colored bright red, while other areas are colored green. This allows you to find and fix problem areas in your design.
The finger test lets you use your finger to push and pull on your design. You can use this with pinpoint accuracy, or you can just smash your design to smithereens. The finger test has an explosive new twist. You can now create explosions by tapping the screen for ultimate annihilation.
The newly added Bomb Shack level includes a dummy with full support for ragdoll physics. Throw him around, blow him up, and smash him against your design.
The slow motion feature lets you slow things down so you can see how your design is failing, and it is also incredibly fun to watch explosions destroying your design in slow motion.
3.8 of 244 reviews are four stars and above.
These apps are compatible with the original Fire and with my Fire HD 8.9" 4G. To tell if an app works for your Fire HD or other Android device registered to your Amazon account, click on the above link and look on the right side of the web page. Amazon will tell you if it will work with your registered device.
Also check out the other digital deals from Amazon, including great deals on MP3s and videos: