Two huge new features: push notifications and you can stay logged in for up to 7 days. I have been testing this app for a bit now and it really is the best IM client you can get on your iPhone. I truly love this app for the few times that I use IM on my phone.
It’s $4.99 for a limited time and well worth it.
Update: The app is $2.99 and the IAP for the Pro is $4.99. My apologies.