Updatecheck plugin is now available as a beta. i.e. your opinion / possible changes are now welcome.
the plugin can be found after the installation under extensions or on the blue button on.
selectable options are the following:
plugin on / off
Periodic examination between 0 and 24 hours will be set to 0, with just bein neustart examined.
permanent display of the popup window shall skunden 0 to 60 where 0 means again that the popup remains on the screen until it is confirmed.