Advanced Scripts
The Advanced Scripts plugin is a code snippets manager with a lot of features. You can add PHP, CSS, SCSS, LESS, and JavaScript code snippets. The SCSS and LESS code is compiled on save into CSS. The plugin also makes it easy to load external CSS and JavaScript files. There is a safe mode that catches any errors and prevents a bad snippet from crashing your site. Advanced Scripts has a special integration with Oxygen that brings the Oxygen color palette into the Advanced Scripts code editor so you can easily pick site colors. Packages are available for 1, 5, or unlimited sites and include lifetime updates and support.