If you find a thread you're interested in, add it to your Checklist to see when new comments have been added.
You can access your Checklist from My Page.
Adding a thread to your Checklist
Tap the icon in the upper-right corner of the thread list or individual thread page to add the thread to your Checklist.
Threads you create are automatically added to your Checklist.
Removing a thread from your Checklist
From a thread
Tap the icon in the upper-right corner of the thread list or individual thread page to remove the thread from your Checklist.
From My Page
Select "Remove" below the last updated date on the right side of the list.