iOS: One of the best ways to make sure you break out of your filter bubble is to read different news sources with multiple perspectives on a variety of topics. Random, a news-reading app for iPhone and iPad, breaks you out by intentionally guiding you to articles at news sites you may not otherwise read.
The "filter bubble", or that insular shield of customised, aggregated news that tends to give you news catered to your world view, can be hard to break out of, especially if you're trying to learn something new or see an issue from all sides. Random gets the job done by presenting you with a series of topics for you to tap and read more about. Touch one, and you'll get either a selection of more detailed choices, or an article to read. When you're done and go back, you'll get an entirely new set of choices, loosely based on the topic you just read. Tap another one to dive deeper and read a different piece.
Random isn't a traditional news app. You don't choose your news sources, and it's not a feed reader. You just choose what you're interested in reading about. The app mixes things up a bit with its topic selections too -- if you're reading about "climate" and then "environment", you might suddenly get an option to read more about "anthropology", for example, and find yourself led to a new and completely different discussion. The end result is that you wind up reading perspectives and news sources you may otherwise never stumble on, and get a better understanding of issues you're already interested in. The app is free -- hit the link below to try it out.