A free program for Android, by My Bear Games.

If you like to solve logical puzzles, this game is for you. In it, you’ll find many different tasks to complete, and you’ll need to use different materials to do so. Build bridges of various materials and sizes, from small to grand, to cross rivers. You can even build a railroad, using the material you get in the process.

You’ll need to use wood, steel, rope, and balloons to build bridges. When you’re finished, you can test your work by setting a limit on the load. Make sure your bridge is solid and sound before you let the steam train pass.