REFILL Anywhere offers a portable charging service for smartphones, resembling the paradigm of shared-bike networks in cities.When low on or out of battery, subscribing smartphone users can go to a refill machine, stationed throughout a city, and rent a power bank charger. Subscribers can then charge their phones on the go. When finished, they deposit the used power bank at anystation. Customers can rest assured that a fully charged battery is attainable at all times. The service eliminates the need to worry about carrying a portable charger or finding apower outlet. The software and hardware is developed in-house. REFILL also offers advertising services on its products.