About
With Outdated Answers: accepted answer is now unpinned on Stack Overflow, I find that it would be nice to have an indicator. Some posts have multiple pages, and searching for the one post among many requires a little too much scrolling.
How it works
The script will check the timeline for an accept event. If it finds one, it will add a checkmark to the post title, as marked in red.
If this variable in the script is set to false:
const addToTitle = false;
the script will instead add a button next to the sorting filters, as marked in pink.
Clicking on the checkmark / button will take you directly to the accepted post.
Screenshot

Sites
Should work across the Stack Exchange network.
Note that the wording of the button isn't locale specific.
Platform
Should work with any user script manager & any browser running JavaScript.
Tested using Opera with Tampermonkey.
Download
Contact
For bugs, please post here. Comments are fine too.