After you print to a PawPrints queue, your job is held for 24 hours. The "Quick Release" link on the app takes you to a page where you choose the destination printer. Releasing to a printer also works from your PawPrints account's "Jobs Pending Release" page.
If you print to a color queue, you may only release at a color printer. If you print to a grayscale queue, you may only release at a grayscale printer.
PRO TIP: Add the release page to your phone's home screen for quick access to your favorite printers.