a useful addition could be to use the prompts to understand why they are feeling a certain way, and then provide them with some call to action on what they can do next to improve their emotions. For example, if a person is feeling very unhappy and sad, and he selects to write a gratitude prompt, after he finishes that, they are provided with a list of things they can do to deal with that situation, it may be trying to resolve whatever was bothering them, etc.
GratiTune