Two-dimensional (2D) ferroelectrics, planar materials that have a spontaneous and reversible electric polarization, are extremely rare and yet could be extremely advantageous for the development of new nanoelectronics. Due to their ferroelectric properties and thin nature, they could be used to create high-performing, small and flexible devices, including high-density non-volatile memory, optoelectronics, ultra-low energy electronics and wearable technologies.