Zoiper is such a great cross-platform, multi-account program that it is slowly becoming our most used and most recommended softphone. You can download the latest version from their download page or, if using a smartphone, from where you normally download apps (Google Play, iTunes, etc).
When you subscribe to our services, we customarily send a Welcome Email with a special link to Zoiper, which allows you to configure your smartphone by simply taking a photo of their generated matrix. We do not make the password part of that install routine for privacy / security purposes, but once you enter it, you are all set. If, however, you would rather configure it manually, the guides below should help.
To setup Zoiper, you need the YourUserID, YourPassword and YourDomain, as explained in Setup. However, for your convenience, we are also providing a visual guide for the most used OSs.
NB: as with most other softphones, it may sometimes be that Zoiper does not allow incoming calls by default; you need to enable a special setting such as "enable presence", "force background" or sometimes "keep Wi-Fi alive" for that to work. In our visual guides that is generally presented as the last step.