The site doesn't just present the median hotel price and room availability. It also identifies when major events are taking place, which could impact prices. Additionally, Offpeak provides weather data to let you know what you're in for if decide to go to Iceland in February. (Cold, but still worth it.)
"The inspiration for Offpeak.io arose when I noticed drastic differences in hotel rates day by day," Adleman says. "It amazed me that the same hotel room went for $100 dollars on one night, and for $400 dollars on another. Of course, one would expect rates to be high on New Year's Eve and low during the cold winter, but they differ significantly on many more days than that."