AccuWeather was just caught sending GPS coordinates, Bluetooth switch, and BSSID of local Wi-Fi routers to a third party. Granting this app access to location information on an iPhone has been found to send several pieces of information to data monetization group Reveal Mobile. While AccuWeather has an extremely large userbase with a strong rating on the Apple App Store, its innards seem to be doing something of which users aren't fully aware.
UPDATE: AccuWeather and Reveal Mobile have released a joint statement which includes the following: "Despite stories to the contrary from sources not connected to the actual information, if a user opts out of location tracking on AccuWeather, no GPS coordinates are collected or passed without further opt-in permission from the user." Further info can be found at the end of this article.