In some apps, you’ll see an option to connect with your Pinterest account. By connecting your Pinterest account to that app, you can easily save and do more with Pinterest.
For example, if you use IFTTT, you can save your Instagram photos and Etsy favorites to Pinterest.
If you no longer want to use Pinterest to connect to these apps, you can always remove access by going to the Apps section in your settings.
Right now you can only connect with Pinterest to certain apps, but be on the lookout for the option to use Pinterest with all kinds of apps and websites in the next few months.