Back Cover: Ruthenium‐functionalized uniform poly(N‐isopropyl acrylamide) microgels with hydrodynamic diameters between 1 and 6 μm are synthesized using a modified precipitation‐polymerization route. Because of their size and fluorescence properties, in situ observation of their dynamical behavior in solutions of NaBrO3 with different concentrations is achievable using fluorescence microscopy. Further details can be found in article 1600577 by Y. Hu* and J. Perez‐Mercader*.