Developed by the startup Caléa, Mood Messenger offers unique features and regular updates, creating a fun and engaging experience for users. With over a million downloads in less than a year, it has become the highest-rated messaging app on the Google Play Store. The company's success can be attributed to its innovative technology, led by CTO Olivier Lhermitte, and its focus on user feedback and support. With the growing popularity of the app, Caléa secured a €2 million investment from French fund IXO in late 2016. Currently, Mood Messenger has nearly 4 million users and is set to be integrated into several phone models in 2018.