Gravit universal binary released for Mac OS X

Gravit is an Open Source gravity simulator I started writing in 2003 and worked on it in my spare time until about 2005. It’s written in C and uses OpenGL, SDL and Lua.

Even though Gravit has worked on Mac OS X for a while, I didn’t get around to actually making a bundled application for it until now. Normally you would have had to compile it from source, usually with some tinkering of the source code and build settings.

The UI needs some more work to make it more like an OS X application, but I don’t have time for it at the moment. For now, here is the gravit-0.5.0.dmg universal binary and a quick tutorial on using it. Don’t forget to hold down the fn key when dealing with function keys, and if you have any problems please tweet them at me. Enjoy!

TowerDefend is now $0.99!

TowerDefend is a game for the iPhone™ and iPod® touch. It is a real-time strategy game based on the Tower Defense genre of games where you build towers to shoot at creeps trying to escape the map.


  • 3 ranges of difficulty for skill and 4 map types, with more to come.
  • 12 types of towers, all with different abilities.
  • Scroll around the map with finger pinching and dragging.

After two years of being on the App Store, TowerDefend has now been reduced to 0.99 USD!

If you haven’t tried it, it’s pretty addictive! You can get it here on the App Store.

Wireless Heatmap

Update: WiFi Heat is available on the Google Play Store! For more information, see

I wrote an application to generate a wireless (802.11) heat map based on signal strength. The reason for it was to find the best place/area (for my laptop) to be with the highest signal strength. Below is a screenshot of the application (with the ESSID and BSSID removed for security reasons).

This heat map has about 100 samples in it, which are shown as white dots. There is a balcony at the top of the image and the common office area on the right, which was drawn by hand (hence the waviness). As you can see it has pinpointed the location of the access point in the red area.

Continue reading Wireless Heatmap