This is a sample app to demonstrate the concept of building a Rails application by ingesting a third-party API.
The API used by this app can be found at http://restcountries.eu/#api-endpoints-all. The specific endpoint that the app consumes from is https://restcountries.eu/rest/v2/all. Before digging into the app, try hitting the endpoint (type the endpoint address into a browser URL bar). If the resulting JSON feels overwhelming, I recommend using the JSONView Chrome Extension. All you have to do is add this extension to the Chrome browser and enable it, and your JSON will become that much more manageable.
The app displays the following information about a random list of countries - country flag, capital, population numbers, languages spoken, which countries are on the border and Lat/Long. (There is more information that can be extracted out from the API (see the section above), but this is what I decided to extract for this example.)
Sure. https://random-countries-info.herokuapp.com/ Every time you refresh the URL a different random list of countries will be displayed. If you would like to control how many random countries will be displayed, you can pass in a limit parameter, for example https://random-countries-info.herokuapp.com/?limit=5
Basically, this is very similar to how the Coursera Courses Listing app was created in Lecture 9 and Lecture 10 of Module 3. And, of course, you would substitute the word countries instead of the word courses. So, for example,
rails g controller courses index
becomes
rails g controller countries index
Take a close look at the Gemfile. For example, you need to specify gem 'pg', '~> 0.20' since for whatever reason the typical gem 'pg' (the latest) is not compatible with Rails, at least not version 4.2.8. (See the following for more info)