Vtok is a messaging and audio- and video-calling app for the iPhone and iPad, available free from iTunes. Using a browser plug-in you can also use Vtok on a Mac or PC. You can use a Google ID to identify yourself to Vtok, although Vtok is not a Google-provided service.
From the Vtok's clean interface you can select the person you want to chat or talk with from a list of contacts, or dial that person's number using the keypad, and then the connection is made. A small bar of icons at the bottom of the screen lets you control voice and video calls, including a small popup window for your feed. For chats, there are a number of emoticons and other artwork you can add to your messages, and you can transfer files easily. As with any such tool, the quality of the calls is dependent on the data transfer rate, but over Wi-Fi we had excellent quality. Vtok stays online in the background so incoming calls notify you by sound. Our only complaint about the app is the color palette, which is varying shades of green: novel at first glance it gets old fast. Also we had to reestablish our contacts list, as Vtok didn't import from our other calling app.
Our testing with Vtok showed this to be a nice app, with features and quality comparable to some of the more entrenched players in this field. With over 3 million users, Vtok is catching on fast. Vtok stacks up feature-by-feature to similar utilities, but whether it compares to the big players in the field is more a personal choice than anything.