From the paper itself: "We used iPhone 4 for the iPhone measurements, and Google Nexus S for Android 2.3 measurements. For our Android 2.2 measurements we chos

From the paper itself: "We used iPhone 4 for the iPhone measurements, and Google Nexus S for Android 2.3 measurements. For our Android 2.2 measurements we chose the Samsung Galaxy S, since it has almost identical hardware to the Nexus S, making the OS the primary difference."