Every now and then I lose a correspondence game on time simply because of rhythm and the fact that the “weekend” or “pause” marker obscures how much time is left in a game for the entire week-end or duration of the pause. Please always, always, always display the time left on every game.
Also have the next board button bring up the board with the shortest amount of time regardless of whether it’s paused, on vacation, or on week-end (great if it does that, but I suspect it doesn’t). Two little changes (the first one crucial) to help a person not end up flat footed on a Tuesday with no idea a game was short on time since Friday.