I'm looking for a tasklist plugin. Is this avaible or do i need to make my own?
I have a some php skill but i don't have a idea how to start this in roundcube. Someone can help me in the right way?
The best way to start is to read the plugin api documentation:
http://trac.roundcube.net/wiki/Doc_Plugins
http://trac.roundcube.net/wiki/Plugin_Hooks
http://trac.roundcube.net/wiki/Plugin_Events
It's also a good idea to check out the code in other plugin for examples. Good Luck!