Users can use the “app” to register their own heart beats by tapping on the app (or automatically through photoplethysmography)*, and the app plays back the heartbeat at the captured rate and gradually changes and moves towards “normal”/healthy heart rate. Users can then listen to this and in a short period of time users who feel anxious or upset can come to a more relaxed state while the user’s heartbeat gets synchronized/entrained (necessary to define this more: https://journals.sagepub.com/doi/10.1177/0748730420972817) with the app’s playback.

Another possible application maybe a rhythm generator (drum machine) by the captured heartbeat/rate. 

*Aim is that the user doesn't need to purchase or use another technology or equipment (a sensor for instance) which can be burdensome and inconvenient to use the application.

Emotion also facilitates encoding and helps retrieval of information efficiently.

Users can highlight a particular paragraph or word of the text and then send a notification to the selected loved ones so that they can record remotely (the person who has to record the voice doesn’t have to be with the user in person). Users can record the voice of someone they love, so that whenever they need to recall a particular paragraph or word from memory, they can think of the voice of their loved ones and retrieve a particular memory. 

e.g. The Influences of Emotion on Learning and Memory