cooltokBangalore-based messaging app startup Cooltok has been acquired by US-based Kirusa for an undisclosed sum. Cooltok announced this acquisition on its website.

Kirusa has acquired Cooltok’s six-member team, that will now join Kirusa’s office in Bangalore. All technology and intellectual property owned by Cooltok was also acquired as part of the deal.

Cooltok was co-founded in 2012 by Sreenivas Karanam (CEO), Prakash Kaja and Thomas Mathew. The company, also known as Plusray Innovations, developed a VoIP product for smartphones that can be used for making free calls, sending text messages, managing voice and group chats and sharing pictures and files. The mobile app was launched a few months ago on Google Play store.

Cooltok app can work on any network, and is similar to WhatsApp – which got acquired for $19 billion by Facebook. Cooltok comes with an additional function of making calls, much like Viber that was acquired by Rakuten for $900 million earlier this year. However, Cooltok works only on Android devices as of now.

Kirusa also has a free messaging and VoIP app called InstVoice that could also be used for sending SMS, Voice SMS and voicemail. The company develops voice and social media solutions for emerging markets and is based out of New Jersey. It works with 35 mobile carriers globally. It is not clear how many active users INstVoice has or how many Cooltok had.