  Measuring energy consumption is a challenging task faced by developers when
building mobile apps. This paper presents EMaaS: a system that provides
reliable energy measurements for mobile applications, without requiring a
complex setup. It combines estimations from an energy model with --- typically
more reliable, but also expensive --- hardware-based measurements. On a per
scenario basis, it decides whether the energy model is able to provide a
reliable estimation of energy consumption. Otherwise, hardware-based
measurements are provided. In addition, the system is accessible to the
community of mobile software practitioners/researchers in the form of a
Software as a Service. With this service, we aim at solving current problems in
the field of energy efficiency in mobile software engineering: the complexity
of hardware-based power monitor tools, the reliability of energy models, and
the continuous need of data to build energy models.
