Quip - Quip is the modern productivity suite that simplifies your life and helps your team get work done faster.
Fuse - Fuse is a UX tool suite for mobile app designers and developers.
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.
Dropsource - Mobile development platform for building native iOS & Android apps
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.
Siberian CMS - Siberian is an Open-Source and Free App Maker. Unlimited Push Notifications. Unlimited features. Fully Customizable. Download it and build your own app now!