What are some alternatives?
When comparing Call Me Private and Viber, you can also consider the following products
Grasshopper - Grasshopper enables entrepreneurs to build a virtual office that connects callers to employees, wherever they are.
Telegram - Telegram is a messaging app with a focus on speed and security. It’s superfast, simple and free.
Line2 - Line2 adds a second phone number or complete cloud business phone system to smartphones & computers that's robust yet affordable. Buy online or get a custom quote.
WhatsApp - WhatsApp Messenger: More than 1 billion people in over 180 countries use WhatsApp to stay in touch with friends and family, anytime and anywhere.
YouMail - YouMail turns visual voicemail into a personal assistant for handling all your missed calls.
Skype - Stay in touch with your family and friends for free on Skype. Download Skype today to chat and call on desktop and mobile.