Vantage is a calendar designed for people who like to think and understand things visually. A lot of attention has been taken to present time in intuitive ways using perspective, color and motion. And it's resulted in some pretty interesting UX solutions.
ClimaCell Micro Weather API is the most granular weather data in the world.
With Timeview you can do stuff like "show me all my events from my work calendar containing the word 'meeting' and with a duration greater than 2h". The possibilities are almost endless and it's really easy and beautiful.