RR Lyrae Studies with Kepler

The spectacular data delivered by NASA's {\it Kepler} mission have not only boosted the discovery of planets orbiting other stars, but they have opened a window on the inner workings of the stars themselves. For the study of the RR Lyrae stars, Kepler has led to a breakthrough. To date, over 50 RR Lyrae stars are known in the Kepler field. They are studied within the RR Lyrae/Cepheid working group of the Kepler Asteroseismic Science Consortium (KASC). This paper highlights some of the most interesting results on RR Lyrae stars obtained through Kepler so far.