It is a client app for hashcat reactor which show real time stats like hashrate, recovered hashes, power usage and temperature, if you are the very few using hashcat and a pebble watch try hashcat reactor which is a GUI for hashcat and use this pebble client app to have the dashboard on your wrist.
Find out more at: https://github.com/jjsvs/Hashcat-Reactor
Project is open source so you can modify and fit it to your needs.