Hockney carried on working until the last, and his most recent exhibition in this country is still open until 26th August and free to visit. It is a 90m installation of 100 iPad paintings stitched together at the Serpentine North Gallery. It depicts in large-scale, glorious colour a recent year in Normandy, and expresses his belief that simple beauty is worth celebrating. It is the work of an older artist, but is nevertheless uplifting, positive, and joyful.