Yes, it has been a while…
But finally I got the time to start working on InboxRuler again and now starting to update to the latest iOS and libraries. I did encounter almost immediately after rebuilding the reason why InboxRuler does not work with gmail anymore. The 2 Factor OAUTH is processed incorrect. Next task on the list!
More updates to follow as I have a bunch of ideas to improve InboxRuler, especially to make the background timer more reliable.