Google launched Science Journal for Android last year as an easy way to measure light, sounds, motion and more. While it already sounded like a great tool, it's now more useful than before: Google has turned it into a full-fledged digital notebook students can use to take notes for their scientific experiments. Each entry now begins as a blank page. Students can add in measurements taken by the app, along with their thoughts and observations, as well any photo they've taken. And since Science Journal is now also available on iOS, almost every student with a smartphone can use it.