I will just quickly point you to a post I made a year ago:

http://talk.maemo.org/showpost.php?p...73&postcount=5

Most things still apply. Only AGTL doesn't work anymore at all.
Also to add to it: Billboard, FileCase and QRadio is also very nice


You can get most of these apps from openrepos, use the warehouse client: https://openrepos.net/content/basil/warehouse

For some you have to trick the certificate system, because of expired certificates. Do this like so:
Search the app which fails in warehouse, open it, don't click on install yet.
Switch to clock, set time to 2012 or something which works
Click the install button and reset the clock to current date when the software is installed.
(You can't browse openrepos with the date that far back, because your N9 will think its certificate is not yet valid)

If you need links to applications not on warehouse, ask here. I will take a look again tomorrow, when I have more time.