[tshering]

This new version is supposed to run from FW 2.6.0 up to 3.8.0.

I have minimally tested it on a Kobo Touch. (Edit: Since then more than three month have past. This version is still running on my device. I would say, it is ok.) Trekk reported that it is working on 6" Aura, and Ken that it works on Aura HD (Thank you both!). Until now, I did not notice any reports concerning other models. I take this as meaning that there are no major problems. (EDIT: Since then I got several hints that it is working on Mini and Glo too; for instance by WS64 and uboot [mini]; by Cyphox [Glo]).

For install and uninstall see post #1.

If you are upgrading from an earlier version of the Kobo Start Menu. Copy the KoboRoot.tgz file to .kobo. Then select "handle update > install update" from the main menu.

After booting, the Kobo Start Menu will be launched alternating with nickel. If you have checked that everything goes fine, you will likely want to change this behaviour, see this post for an explanation.

Be aware that you cannot easily downgrade the Kobo firmware without doing a factory reset. The reason for this is that the Kobo Start Menu tries to work with all FW versions starting with 2.6.0. In order to do this it determines the currently running FW version by looking whether specific files are available on the device. After downgrading (without factory reset), these version specific files are still living on the device, and this fact results in false identification.

Spoiler:

I have disabled (the otherwise automatically enabled) Night Mode for FW 3.3.0. At least at my Touch, the Night Mode works, but after opening a book the device freezes. If you want to try it, set enableNightmodeOn300plus (sic! yes I did this typo) in .kobo/kbmenu/onstart/startreader.sh from false to true.
Edit: I just found that the night mode seems to work on my Touch (and presumably on all other models), if toggled by the home/light button rather than by fmon. For the convenience of those who don't want to edit the startreader.sh by themselves, I upload the modified version here. Extract it from the archive enable_night_mode_andRebootAuraHD.zip and replace .kobo/kbmenu/onstart/startreader.sh with it. If you use this version of the startreader.sh Aura HD will reboot when you select exit_nickle.png from nickel.
This has been replaced by the update package 01

NEW: There is an update package available for this version that provides further functionality. (By the way: no need to install enable_night_mode_andRebootAuraHD.zip anylonger). You can find there also uninstall files for more recent firmwares.
NEW: You can find scripts for changing the time zone in this post.
NEW (2014.08.19): Please use this script for better integration of koreader.

The Kobo Start Menu is not compatible with KoboMultitouch320.

USE THIS PACKAGE AT YOUR OWN RISK!