Playtime Booster

The Playtime Booster feature allows you to idle one or more games manually to boost their total playtime.

When idling games with Playtime Booster, external SteamUtility (idle) processes will be opened to interact with the Steam client and imitate game processes. These processes will be closed when the game is no longer being idled.

You can idle a maximum of 32 games at once. This is a Steam limitation

Steps

Click in the sidebar

Hover over the game you wish to boost playtime for and click

Click in the sidebar to view the games you are currently idling