AutoQoS

AutoQoS is a daemon app that will sit in your system tray and allow you to create, edit, or delete QoS rules on Windows 7 and above. These rules are used to prioritize network traffic on your machine. Normally this is done at the router but not everyone has access to those settings and not all routers are easy to configure.

This program is useful if one application tends to slow down traffic to other applications you are using. Downloading something in the background and it's slowing down your game? You can increase the priority of the game's traffic and play as if that download wasn't happening! There are lots of cases where a local QoS is ideal.

Download: AutoQoS.exe

Source: AutoQoS.ahk (written in AutoHotkey)