BROOKLYN - A free smartphone app could be making wallets a thing of the past.

LevelUp allows users to pay at a variety of businesses using just their phones instead of cash or plastic. After downloading the app, shoppers simply have to link it up with their debit or credit cards.

The system is gaining traction among several Brooklyn businesses, including Luscious Food in Park Slope. Many shop owners say the fee costs are relatively the same when compared to a Visa or MasterCard, but with LevelUp, they get the added bonus of advertisement through the app's rewards program.