Trackerchecker.org - we follow the registrations on torrent trackers

It's no secret that for registration on closed torrent trackers, invites are needed. However, some of the private trackers open free registration on certain days of the week or certain hours. Keep track of this is quite difficult. The Trackerchecker.org resource can help , which tracks the opening of registrations on more than 500 closed trackers and informs you about it.

UPD: Hubman man centolla has announced another similar resource - www.opentrackers.fr
UPD2: Habrochelovek Iforgot gave a link to an interesting resource for sharing invites to closed trackers, which also contains information about trackers - www.zeropaid.com