If you want to inject your own user code into a specific website, then this Chrome application might just be what you need. This extension for the Chrome browser allows you to insert your custom JavaScript code into almost any website you desire. Simply enter your code, and then you can either save it by clicking on the save button or by letting it be automatically saved.

The extension's user interface is easy on the eyes and simple to navigate. It comes with jQuery and ace editor. To install, simply click "Add to Chrome". You can right-click the icon to access different settings.