I know there's been a thread or two like this in the past, but since I've noticed some new users who are just now purchasing N8x0 devices I figured covering this again couldn't hurt. This thread is intended for apps not found in the standard repositories, but ones hidden through out the forums or elsewhere on the web.

Slide-Rotate: Automatically rotate the screen from portrait to landscape when sliding out the keyboard on the N810. When the keyboard is replaced, the screen will automatically rotate back to portrait. You can also assign a the Home or Power button to rotate the screen as well, making it useful on the N800 as well. It works best if installed after the Community SSU. Also, it breaks compatibility with Diablo-Turbo if ASUI is installed,meaning you have to re-install Diablo-Turbo after installing Slide-Rotate.

Gene Cash's PIM Apps: Calendar, Checkbook, To Do and Database applications. Most people seem to prefer GPE or Seqretary for their calendars for the Home Screen applets. What I like about this calendar is that it automatically opens every night at Midnight, so 1st thing in the morning I can see what needs to be done that day and for the next 3 weeks. The checkbook is THE killer app for me; I can balance all of my accounts on the N810 and have for the past year and a half. These apps do have a bit of a learning curve, especially the checkbook app, but I feel it is well worth the investment of time for the utility they offer.

Picodrive: A multi-system Sega (Megadrive, Genesis, CD) emulator. It is command line only for Diablo, but it works better than most of the other emulators for N8x0 out there. This post by Addison has the scan line codes for the N800; the directional codes are the same for the N810, which means you can have a full screen Genesis emulator on your tablet. This makes me wonder what other apps have been back-ported to Diablo buried in these forums.

Color ls: Provides colors for the default terminal when using the ls command. makes navigating the command line much easier for those times you have to.

Yellow Notes: Multiple (up to 99) sticky notes on your Home screen. I use this for my shopping lists, wish lists, workouts and anything else I need a simple text note for. It's awesome.

Applet Lock: This locks the position of your desktop applets. This should have been provided by default by Nokia; thankfully, someone found a way to provide this utility. It does need to be reset every time you reboot your tablet, but otherwise it is golden. This needs to be installed after the Community SSU.

Community SSU: I include this because despite it's popularity around here, information on how to install it requires digging through multiple threads on the forums. The biggest advantage I see is the ability to rotate my screen, but I consider that a huge requirement in how I use my device.

That's all I got. Hope this helps some of the newer users around here.