While not directly focused on increasing happiness, Tidepool is an app that encourages/improves emotional intelligence, especially at work. In a game-like environment, users (above) determine their dominant personality traits, helping to better match them to colleagues at work.
A second game lets users see a photo of a person's face and rate their emotional expression. As the game gets faster, users have less time to assess how others may be feeling based on their expressions in the photos in the game. The app encourages people to reflect on other people's emotional states as a way to improve empathy as well as workplace productivity. As altruism and compassion are shown to increase happiness, this means users can improve their happiness while helping their colleagues do the same.