Cellular data networks are increasingly being used for Internet access. Various analysts suggest that the number of mobile Internet users will soon surpass the number of conventional fixed-line Internet users. No doubt, understanding the quality of Internet connectivity provided by currently deployed cellular data networks is important for all stakeholders including the users, operators, and policy planners. Towards facilitating the aforementioned, we have developed smartphone applications for both Android and iOS platforms that can perform a range of network measurements and diagnostics such as upload/download bandwidths, latency to landmarks, DNS resolution times, and identification of NATs. Widespread use of our application will enable ”crowdsourcing” wherein measurements from different users and networks can be studied and compared. For example, crowdsourcing allows a user to compare his or her average upload/download bandwidth with that of other users using the same operator, and also with those achieved by users of other competing operators. We believe the data available from use of our application will provide valuable insights on the state of today’s cellular data networks.