I use TapaTalk for IP and my Audi forum so maybe I can help.
1. Start app and go right to new threads on my favorite forum
Once you're in your forum...tap the 3 horizontal bars on top left then choose 'unread' or 'subscribed'.
2. Press one icon to Mark All Read
While in Unread tap the check mark on the top right to mark all as read. Press and hold that check mark for instant mark as read.
3. Can't figure out how to post a new thread!
While in the forum you wish to create a new thread...Tap the 3 dots on the top right to create new thread, unsubscribe or mark as read.