Platforms: iOS, Android, Windows 8 (all free)
Evernote is the quintessential paperless app. It helps you get rid of unnecessary pieces of paper such as receipts, lists, and napkin-contracts. Take notes, make lists, photograph receipts, clip Web pages, and save pictures to your account using your tablet. Evernote syncs all this data across multiple devices for access anywhere. It even reads your handwriting and converts it to plain text. Pair it with a Livescribe smartpen to save paper notes to the cloud, and you can recycle the original notebook. Coming soon: Evernote is building intelligence into its apps so that it can recognize the types of documents you're storing there.