Question of the day #425

• X is a unique startup founded in 2010, which specializes in the mobile marketing and user intelligence niche, the foundation of which is based on missed calls. 
• X’s clients include Unilever, Disney, Gillette, Amazon, Facebook etc.X represent a small yet high-profile acquisitions of Indian startups by global technology giants. The acquisition was valued at $30 million.

     Identify X?