Most Firefox users know that they can search for contents on a page with the help of the keyboard shortcut Ctrl-f. This triggers a search form at the bottom of the page that searches for the term that is entered into the form. Once you start typing in the first character you will notice that Firefox highlights the first occurrence of it on the page. You can use the F3 key to jump to the next occurrence, or Shift-F3 to jump back one hit.
You can also trigger the on page search by clicking on Edit > Find and using the buttons available to flip through the search results. The bottom bar has two additional options, one highlights all occurrences of the search term on the page, the second makes sure that only those that match the case are included.
One of the things that you may be missing is an ability to access previously entered search terms again. This can be very useful if you search for the same terms regularly. This may be the case for researchers, brokers or students, and anyone else who uses the same search phrases over and over again.
The Firefox add-on FindList adds that functionality to the web browser. Once installed it remembers the last 50 searches that you have made on web pages. Keep in mind that old terms get flushed out once you hit the 50 terms mark.
All recent terms are displayed in a selection menu once you activate the search form after add-on installation.
Some users may dislike the feature as it can be a privacy nightmare, especially so if other users have access to that user profile.