RingGo
RingGo is a pay by phone parking service, based in the UK. Technology

The system is used by local authorities for on-street parking and public car parks. The smartphone application requires that users log both their arrival and departure time and failure to remember to sign out can lead to an overcharge. It has also been suggested that councils that use RingGo are unfairly penalising users who find the technology difficult to use. This has meant reduced customer numbers in some shopping centres that switched to smartphone-only parking. References

External links
 RingGo website

Mobile technology
Parking companies