PayPal has updated its iOS and Android apps to focus a lot more on mobile payments. When starting the app instead of just showing you your account info, it shows you local shops that accept PayPal payments.
When you're at a store you can check in and pay for your goods right away without having to handle any physical cash or cards. If stores allow, you can even pay for your goods in advance and then pick them up when they're ready.
You can choose what form you would like to pay in. You can either use your PayPal balance or any number of credit and debit cards that are connected to your PayPal account.
The app is actually a brilliant way to pay for things and makes some processes a lot quicker. Unfortunately not many shops have yet integrated PayPal into their checkouts, and there is of course the other problem that many don't want to trust PayPal with their cash.