WhatsApp, now claims to have 50 million monthly active users in India and announced that it crossed 500 million active users in April, out of which it added 50 million since February. The app has also entered a deal with Airtel to offer subscribers WhatsApp-only data packs. Airtel is offering up to 200MB of WhatsApp usage for one month depending on the circles. Its for Rs. 36 for a month and go up to Rs. 49 per month.

That number could rise even further when Whatsapp brings voice calling to the app. WhatsApp may not have stickers or random chat like some of its rivals, but the voice-calling feature could end up cementing its dominance in the space.

Airtel subscribers' can activate the new WhatsApp data tariff by messaging 'WhatsApp' to 121. It is available for both 2G and 3G users but not many details have been listed.

The app which was acquired by Facebook has seen quite a steady growth in India.