| Uprecords | | - | | |
| Unzip | | - | | |
| Unpacked extension development | | - | | |
| URL Saver | | - | | |
| URL Relay | | - | | |
| Typing Stats | | - | | |
| Typing Speed | | - | | |
| Todo | | - | | |
| Toast Notification Alerter Add-on for Windows 8 | | - | | |
| Tiny Todo | | - | | |
| Tiny Calendar | | - | | |
| TimestampDecode | | - | | |
| TimerFox | | - | | |
| TimeStamp Converter | | - | | |
| Time Blocker | | - | | |
| Tilt | | - | | |
| Tic Tac Toe | | - | | |
| Theme Test | | - | | |
| TextNotes | | - | | |
| Text Holder | | - | | |
| Tetris in Popup | | - | | |
| Tea Timer | | - | | |
| Task Information Collections | | - | | |
| Tangofox Extras | | - | | |
| Tangerinefox Extras | | - | | |
| Tamper Data Icon Redux | | - | | |
| Take A Break | | - | | |
| TaggingNotes | | - | | |
| TagSpaces | | - | | |
| Tab Scope Tweaker | | - | | |
| Tab Notes | | - | | |
| System Monitor | | - | | |
| Super Mario Browser | | - | | |
| Sun Cult | | - | | |
| Stylish-Custom | | - | | |
| Stylish Tools | | - | | |
| Stylish New Userstyle Button | | - | | |
| Stylish Developer Tool | | - | | |
| Stopwatch | | - | | |
| Sticky Plus Highlighter | | - | | |
| Sticky Notes by TSL | | - | | |
| Sticky Notes | | - | | |
| Splash | | - | | |
| Slow Startup Logging | | - | | |
| Simple-Calculator | | - | | |
| Simple Timer + Clocks | | - | | |
| Simple Timer | | - | | |
| Simple Text Editor | | - | | |
| ShinkeiSuijaku | | - | | |
| Shim Storage | | - | | |
