Have you ever found yourself wanting to save your place on a long web page so you could come back to it later and finish reading without having to hunt for the place where you left off? Neither have I, but someone somewhere might have wished for such a capability, at some time. Placemarker was written for that person.
Say you’re reading a long article on VanityFair.com—a site that frequently posts excellent articles that are sometimes too long to read in one sitting. What are you supposed to do when you need to interrupt your reading for more than a few minutes? You could just keep the browser tab open, but what if you need to close Safari for some reason? I suppose you could reopen the web page and use the Find command to search for a phrase you remember from where you left off. Sure you could.
Now there’s a better way. With Placemarker installed, just select (highlight) a few words at the place where you want to continue reading next time. Then right-click (or Control-click) the selection and choose “Placemark This” in the context menu. Placemarker will create a special “placemark” URL and send it to Instapaper, Read It Later, Pinboard, or Delicious, whichever service you prefer. (You need to have an account with one of these services and be logged in to it, or Placemarker won’t work. But you don’t need to have the service’s web site open at the moment of creating the placemark.)
Later, when you open the bookmark in your bookmarking service, Placemarker will find the phrase you selected before and make Safari scroll the page to that point for you. It’s like magic! To make the phrase easier to spot, it will be highlighted with a yellow background. To remove the highlighting, just click the phrase.
Note: Placemarks only work if the Placemarker extension is installed. If you open a placemark on a different computer than the one on which you created the placemark, the second computer must also have Placemarker installed on it, or Safari will not auto-scroll to the placemark location.
Also note: When you open a placemark, Safari will scroll to the first occurrence of the chosen phrase on the page. Thus, for best results, when creating a placemark, try to pick a phrase that is unlikely to occur elsewhere on the page. (Example of a good phrase: “Four score and seven years ago”. Example of a bad phrase: “and”.)
Note this too: It would have been nice to have Placemarker create placemarks as Safari bookmarks in addition to (or instead of) Instapaper or Read It Later items. But Apple made it impossible for extensions to create or otherwise interact with bookmarks. Still, if you want to save a placemark as a Safari bookmark, you can. After using the “Placemark This” context menu command, just bookmark the page as usual. Since the page URL will have had the placemark appended by Placemarker, Placemarker will be able to find your placemark when you open the bookmark later.