Plutoview - Shared browsing solution for remote group collaboration
Quip - Quip is the modern productivity suite that simplifies your life and helps your team get work done faster.
Pop - Super fast, lo-fi video texting with close friends
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Office for Tablets - Get Microsoft Office on your Android tablet
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.