You probably typically pin recipes and ideas you want to try or things you want to buy on Pinterest. Its new button, however, was designed to keep track of the things you've already bought or tested out. Now, when you want to share your feedback about a recipe or a DIY idea you found online, you can tap the new checkmark button on Pinterest's menu to signify that you've already tried it. The app will then ask you how it went, and you can tap on either "Loved it" or "Not for me" and leave a note or tip for other users.