After what period of time do threads in "I'm on" and "watching" disappear on the iPhone app? Is there a set amount of time? My list seems to be quite small now; I'd saved threads there to check back on later and lots have gone. I can't always remember them to search as I'm not always that invested, I just think if I pop them in there I can have a look later for updates. I never know if a thread ended up deleted (happens a lot!) or just "expired". It's quite irritating 