Wikipedia
The RioCard (Bilhete Único) is a smartcard system used in the transport system of Rio de Janeiro state, Brazil. The card is contactless and uses MIFARE technology. It is a form of electronic payment produced and distributed by the Fetranspor company, in cooperation with Itaú bank. Its installation was seen as strengthening Brazil's connection with the Open Standard for Public Transport (OSPT) Alliance.
In October 2013, Rio de Janeiro launched a trial run for this ticket to be run on smartphones, using near field communication (NFC) technology. Around 200 users of the ticket on buses, trains and ferries were selected for the trial, which involves putting a Motorola Razr D3 within a few inches of the reader terminal. Users can then check the balance of their card. Soon, one will be able to prepay fares by using one's phone.