Model Solar System is a simple app I use to teach the scale of the solar system to astronomy students. Simply enter the size (in inches) that you wish to use for your "Sun", and the scaled distances and sizes of the planets will be generated. You can then measure it off in your own neighborhood.
Alternatively, you can enter the total length you want for your model, and the app will scale the solar system to fit. This lets you lay it out in a classroom, football field, etc.
You may be amazed when you're able to visualize the true distances in our solar system!
