Migrating from Nokia to Blackberry left me in an urgent need for a SIP/VOIP client for my new Blackberry. It came to me as a disappointment to find non. My Nokia E61i has this functionality built in and integrated in the phone. All you had to do is enter your SIP phone providers’ settings and off you go.
Not so easy with the BB. All clients that I managed to found were tied to a certain provider. And the generic ones had a terrible audio call quality.
Until I stumbled upon VMOBILE, which offers generic SIP/VOIP clients for BB, iPhones and Android smart phones. The client is small, easy to use and has a great call quality over WIFI and 3G.
Go check it out, it has a 14 days free trial with great support.