1. Phun 2D Physics Sandbox
This free download allows you to model many physics concepts and discover what happens. You can build a boat and see if it sinks or floats or design a bridge and find out how much weight it can hold. Check out this video to see some amazing examples of what you can do with this application.
2. Histografica, Picture the Past
Use this free archive to find photographs of places around the world. Look up an image by location and Histografica not only shows you the image, but gives you its location on a Google Map. Join this community and share your images of the past. Add your picture today.
Image: "Main Street Donegal, Ireland 1930" by thearchiver on Histografica http://www.histografica.com/view.aspx?p=n3jvonui