Lets you change the fps in a scene. Instead of using time remapping, Reflow changes the animation data. It offsets keyframes, markers and fixes NLA lenghts and the scene's endframe. Time remapping makes timeline scrubbing weird and animations get cut because the frame's end isn't updated. Changing the keyframes is more "permanent" but avoids the wonkyness.
A theme I've made and I've been using for several years. It's based on the Base16 Tomorrow Night theme.