Kurzgesagt is a science channel on YouTube that creates education videos for people. They recently partnered with Wait But Why to create the Universe in a Nutshell app. It lets people explore size by zooming between scales of 10^-35 meters to 10^26 meters (atomic scale to universe scale). It’s also filled with science facts that you can find by tapping on the objects you see. App Store: US$2.99
Check It Out: Discover Your Place in the Universe With the Kurzgesagt App