As a very simple mobile user - I don't really chat online much while on the go - I was searching for an ICQ client that would be small, easy, and fast.
IM+ was too obese, slow, and constantly wanted my geo location (didn't like this at all (( - no idea why an IM app would want to spy on my location... )
Beejive - Hm... you've gotta pay $9,99 only to get the idea how it works. No that I'm greedy, but that ain't the way to go.
There's also a bunch of apps like Fring, Palringo, and such. I don't really understand their "ideology" - why would I need to create an account for their service to use my accounts in IM services. Besides, these apps are very heavy.
I was desperate at first, because there was no app simple enough to be used. If you've tried going back and fourth between IM+ and any other app, waiting for the IM+ monster to load and interrogate your location, you understand me...
But there it is! SimpleIM - the down-to-earth, small, super-fast ICQ client!! The app costs $0,99, and does what it says - connects your ICQ account, supports UNICODE, can cut & paste from the chat window.
If you use ICQ only, and need SPEED and simplicity - take a look at Simple IM: