Useful edu apps - Torus Games (maths)

Before we start this is a Torus.

It's a three dimensional shape with only one face (a bit like a sphere). 

In Torus Games (free) you can play all sorts of games such as noughts and crosses, pool, 5-in-a-row but with the added twist that the board is torus shaped so has no edges. Therefore you can win noughts and crosses like this:

Weird, huh?! This is because the right side loops back round to meet the left side, even though the board looks flat. I think this would be great for children to develop their thinking about strategy and 3 dimensional space. It would be great for kids to develop it further and do some research into the Torus and perhaps have a go at drawing one in Google Sketchup or (slightly more advanced) modelling one using Geogebra.

It's also possible to change the settings and play the game on a Klein bottle: