You can bookmark media (gifs, photos, and videos) from stock or import on PlayPlay to find them from one project to another in the PlayPlay library.
To bookmark a media, import them into the library or use the stock.
When you hover over a media, click on the heart icon that appears on the top left of the selected media. The addition is confirmed when the heart turns red.
To remove a media from your favorites, just click again on the heart icon to deselect it.
Then, to find the media you have bookmarked in all your videos, go to the Favorites tab of the library.
You can add as many media as you want to your favorites.