| SoundCloudPlayer | | - | | |
| SoundCloud Player | | - | | |
| SoundCloud Downloader - Technowise | | - | | |
| SoundCloud Downloader - SC DOWNLOADER | | - | | |
| SoundCloud Downloader | | - | | |
| SoundCloud Control | | - | | |
| SoundCloud Continuous Play On-Off Switch | | - | | |
| SocialMetrics for Firefox | | - | | |
| Social bookmarks | | - | | |
| Social Share Counts | | - | | |
| Social Share Counter | | - | | |
| Social Friend Finder | | - | | |
| SnipR | | - | | |
| SmartVideo For YouTube | | - | | |
| Smart Pause for YouTube | | - | | |
| Skipity | | - | | |
| SkipScreen | | - | | |
| Skip to YouTube All Comments | | - | | |
| SitesLike | | - | | |
| Site Searcher | | - | | |
| Simple Translate | | - | | |
| Simple Smartbookmark Addon | | - | | |
| Simple PageRank | | - | | |
| Simple Gmail Counter | | - | | |
| Simpl URL Shortener | | - | | |
| Similarius | | - | | |
| SimilarWeb | | - | | |
| Similar Sites | | - | | |
| Similar Site Search | | - | | |
| Shrtl | | - | | |
| Show Youtube Title On Hover | | - | | |
| Shortly URL Shortner | | - | | |
| Shorten URL | | - | | |
| Shortcuts for Google Products | | - | | |
| Shortcuts for Gmail | | - | | |
| Shortcut Keys for Google Search | | - | | |
| Short URL in one click - hsu.su | | - | | |
| Shoptimate | | - | | |
| Series Searcher | | - | | |
| SeoQuake | | - | | |
| SelectiveDict | | - | | |
| Select and translate | | - | | |
| Select Text and Request URL | | - | | |
| Searchonymous | | - | | |
| SearchWith | | - | | |
| SearchTweaker | | - | | |
| SearchStatus | | - | | |
| SearchMage | | - | | |
| Search the current site | | - | | |
| Search on Discogs | | - | | |