I've got a Q10 and my partner has a Q5. We have been using BBM Video which is great but does it cost anything to use or is it free? I don't wanna get stung with a big mobile bill!
If you are on wifi it's free but if not then is uses up a good deal of data. There's an option in BBM settings to select "allow BBM calls over mobile network" which you can set to off just to be on the safe side.