Started in London, this must-have navigation app has now expanded to 12 other cities, including Paris, Rome, New York, and Mexico City. Not only does it give every option to get from Point A to Point B, including local bus and subway routes with approximate time, Citymapper also presents walking and biking options with calorie counts. You can now book a taxi straight through Citymapper thanks to the latest trend, linking apps through an API (application programing interface). For example, on Google Maps, you can make restaurant reservations with OpenTable. Be on the lookout for more of these symbiotic connections.