DSiExtensions has is exactly what it says in the name: extensions for the DSi Browser. Some of these (eg, calculator) can be used when when you are not connected to the internet! There are also mod packs for the DSiPaint chatrooms to change the colours.
I have written the site myself and checked it through to debug it, if you do find a problem in it please contact nxt1@hotmail.co.uk. I haven't used any templates so it does actually work.
Visit it at: http://onlinedsi.vistapanel.net
Avatar! Yes, I created the very first DSi Browser extension! (http://dsiextensions.co.cc)
These extensions are real nice! As soon as I 'downloaded' them, I began crafting my own. I made a combination of DSiPaint Mod C+ and N+. I made one where you can change the background colors of DIV's named bottomscreen and topscreen, handy for DSi sites. I'm going to start developing DSiTabs mods and have already developed 'themes' for my Windows DSi and DSiMac virtual PCs. I am going to create my own expansion packs for the DSi Browser, submit some to DSiExtensions, and put all on my site, DSiPlaza, for users to use. It's quite easy to make them, you just need JavaScript knowledge. I enjoy 'downloading' your extensions and customizing them to be my own. Keep up the great work!