Citymapper has become a life saver for those of us that live in cities, as well as tourists visiting other countries. The app gets you from point A to B using the public transport systems in all supported cities, whilst also offering information like how much it would cost to get a cab, or how long it would take to cycle there. However, the real draw of Citymapper is that it offers a number of possible journeys with different rules, like bus or train only.
In iMessage, you can send your current location or a location you’ve recently searched for in the Citymapper app to a friend. When your friend taps on the map link provided, it’ll search for directions to the location from wherever the recipient is, although they’ll need Citymapper installed to use it.