βTap: back-of-device tap input with built-in sensors

Abstract

We present βTap, a Back-of-device (BoD) tap detection software for mobile devices that uses commodity sensors, without the need to instrument the device. Although just basic interactions are supported (namely, single and double taps), βTap is highly accurate and performance-friendly, since it uses a low-cost yet highly discriminative set of features. Our software is publicly available at the Google Play Store, so that others can build upon our work.