Slow Android applications cause customer frustration, Frustration leads to less frequent use and uninstalls. One easy step to improve the performance of your application is to identify assets that are transmitted over the network and to optimise them. In this talk, we will walk through approaches to test your mobile app's data footprint and provide suggestions on how to make improvements to lessen the data usage and speed the delivery of assets over high latency mobile networks. After this talk, you'll understand why this testing is important, several techniques to test, and some "gotchas" to look out for.