I am considering your product Zoiper 3 (33.10 price point) for my customers and the Zoiper IAX SIP VOIP Softphone for Android. Both your free and paid products seem to be viable solutions.
Prior to testing I would like to know if your free clients (Windows and Android) contain any adware (be it popups or within the program itself). In terms of privacy, the rules are pretty strict in Canada so for the free softphone, is any of the information that is typed in the software (DID, email, user profile) used for your direct marketing or for 3rd party marketing?