When you install a game on Steam, the client also downloads the required codecs and runtimes. Even if they’re installed already, a new copy is downloaded for each game. These remain in each game’s folder, meaning that a lot of storage space is wasted as your library grows. Steam Cleaner is a sweet little app that scans for these codec files and removes them with a single click. When I first ran it, I was able to recover nearly 7GB of space. It even works with other game clients such as Origin, GOG Galaxy, and Uplay. Sweep it up by going here.
Steam Mover is a useful little app designed for moving Steam games from one directory to another, without the client getting itself confused. It’s best when you want to move games from one drive to another. Say, for example, that one of your drives is full, or that you got yourself a spiffy new SSD and want to run your games on it without reinstalling. This app is basically just a front-end for a batch of move commands, but it’s attractive, easy to use, and great for less technical PC users. Move your browser over here to get it.
Another app that’s most useful if you’re dealing with a massive library with at least a few hundred games. Steam allows users to create custom categories for their games, or even hide them entirely. Depressurizer basically automates the process, assigning your games to predefined categories or to those of your own choosing. It can also help narrow your search if you’re in the mood for a certain type of game, but don’t know where to start looking. You can get it here, no pressure.