Playnite_EgsFreeGamesChecker
This extension will add a tag to Epic games given away by Epic Games Store, based on a custom list and Is There Any Deal API if the game is not found in the list.
It doesn't match all games perfectly as it's based on their name and sometimes the name in Playnite will not be the same as in the list. If you find some games that are not correctly tagged, you can create a issue and I'll add them to the list.
The label of the tag can be set when launching the script from the menu, and it's saved. If you rename the label in Playnite, be sure to rename it also in the popup that appears when launching the script.
The process can take some times if you have a lot of games in your library. When the process end, a message is shown with the number of games found and tagged.