Researchers have devised different interventions to help users regulate their emotions. However, many of the current interventions require a lot of attention and effort from the users, which may affect their concentration during ongoing tasks and even increase their stress. Therefore, a crucial question that arises is: How to design mobile interventions that can help users to regulate their emotions in real-time, without compromising their behavior or cognition? In this project we argue that it is possible to do that by developing mobile interventions that focus on implicit emotion regulation, in which users are able to regulate their emotions without the need for conscious supervision or explicit intentions. In particular, previous studies show that the way we perceive our bodily signals can directly influence our emotional experience. Inspired by these previous studies we designed and built EmotionCheck, which is a watch-like device that can help users to regulate their anxiety by changing their perception of their own heart rate in a subtle way.