If you're visiting Europe for a while, it's fun to visit several cities in one trip. Eightydays helps you plan a multi-city trip quickly by picking a route and finding travel for you.
When you first open the app, it will ask you to pick a city to start and finish in (for right now you can only pick one city for both your beginning and end points). Then pick when you want to travel and how long you'll have. The site will then generate a travel plan with a list of cities you can visit. It also shows flight information as well as AirBnB rates so you can get around and find a place to stay in each city.
If you don't like the plan the site comes up with, you can shuffle for a new one. You can also choose anywhere from two to five cities, if you'd rather spend more time in fewer cities. There's not much else to customise, but that's part of the beauty of the site. It lets you spend less time meticulously planning a trip and more time enjoying it.