Wikipedia
OpenSignal
OpenSignal is a company that specializes in wireless coverage mapping. The company crowdsources data on carrier signal quality from users who have its consumer mobile application installed. Consumers can view the crowdsourced data either online or in-app in the form of colour-coded maps that aid purchasing decisions by showing unbiased data from different carriers side-by-side. In 2013 OpenSignal was named the "UK's Most Innovative Mobile Company" by UK Trade & Investment.
In August 2014, OpenSignal raised a $4 million Series A investment from Qualcomm Ventures, OATV and Passion Capital.