Dark Sky uses your iPhone's sensors to improve weather forecasts

Dark Sky (or rather, its website) on the iPhone

Your iPhone gives you weather forecasts right from the get-go, but it's now ready to shape those forecasts as well. Dark Sky has given its iOS app a big overhaul that, if you like, uses the barometer on your iPhone 6 or 6 Plus to contribute pressure readings. The hope is that these will dramatically improve short-term forecasts in the future -- you'll know that it's about to rain because iPhones nearby gave you a heads-up. There have been apps that crowdsourced pressure data before, but rarely with the intent to directly improve forecasts -- and not on the scale of Dark Sky, one of iOS' best-known weather tools.

It might be a worthy update even if you don't plan to contribute. There's a brand new visual layout, as you'd expect, but you can also create custom notifications for big weather changes, such as a sudden drop in temperature or strong winds. It'll track the UV index, too, so you'll know to pack sunscreen for that trip to the beach. Dark Sky will cost you $4 if you aren't already a customer, but that small expense could pay off if it saves you from getting soaked by an unexpected storm.