I was wondering the same. Also curious about those battery stats:

> Battery currently at 80% (a decrease of 6% in the last 4 hours).

That's gotta be an OLED screen at lowest brightness or, even more likely, a fully black overlay app since the mic is constantly active and either locally processing it into Shazam and streaming fingerprints or (less cpu, more network) streaming it to a server which then does the processing and queries Shazam. As a comparison, my work phone is off+idle basically the whole time and takes twice as long to charge at a higher wattage as my personal phone (i.e.: large battery by my standards), and that uses nearly a percent per hour while the screen is off with maybe 20 messages and one email coming in across 4 hours.

I'm amazed by the idea, that no rate limit has kicked in on Shazam, that they didn't connect it to a power source, and that the battery is lasting so long!

Edit: missed that it is being powered by a solar panel