The ability to be able to have this app open in my phone all day long, without any issues or errors that would stop me from using it as intended! I love how simple yet effective everything is about harpo-therapy! It's amazing for patients who are having problems with their anxiety like myself, but also great if you just want some good meditation time throughout your daily routine! There isn't anything i dislike so far since its been very easy going through each step of getting started! Great product overall!! And definitely worth checking out because there really aren't too many other options available when trying to get into meditative practices such as these ones offered by harpo-therapy!