The Fermi All-sky Variability Analysis (FAVA) is a procedure developed to systematically study the variability of the gamma-ray sky measured by the Large Area Telescope (LAT) on board the Fermi Satellite. FAVA compares the number of observed gamma rays in a weekly time interval at any point in the sky to the number of gamma rays expected from the average emission detected in the entire period of LAT observations. The main strength of this approach is that it is not sensitive to the modeling of the Galactic diffuse emission, which is the largest source of systematic uncertainty for the standard LAT analysis. We applied the analysis to the first 47 months of LAT data and derived a catalog of flaring gamma-ray sources. The catalog has a total of 218 sources, out of which 27 are located at Galactic latitudes smaller than 10°.