Verviant worked on Tawk widget, an Iphone Application that introduces the concept of call buttons, where instead of giving someone your phone number., you give them your call button. They will never need to know your phone number , you can change your number,  but the call button remains the same.

Other features on this Application include conference and group call buttons, conference calls, sending message, block a contact from calling among others. To view a video of the Demo, click on the image.