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.
Zeplin - Collaboration app for UI designers & frontend developers
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
Abstract - A secure, version-controlled hub for your design files
Wondershare PDFelement - All-in-one PDF editor
Mightytext - Send & Receive SMS Text Messages from your computer. Sync'd with your Android #