While Flutter makes apps beautiful and fluid, and Dart makes it easy to program, in most cases we still need some interesting data to work with.  Fortunately there are many useful data sets available across the internet, and the  best catalog of these web services and remote APIs is at:  https://www.programmableweb.com/.

A favorite has been the data behind millions of global patents accessible at the European Patent Office (EPO).  ProgrammableWeb’s page on this is at: https://www.programmableweb.com/api/open-patent-services.  This is a nice exercise in working with  large REST/JSON or XML datasets.