Letters is described as 'drop-in solution which brings you distraction-free writing and real-time collaboration to your favourite CMS or a custom-made application' and is an app in the Office & Productivity category. There are more than 10 alternatives to Letters for a variety of platforms, including Online / Web-based, Android, iPhone, Android Tablet and Windows. The best alternative is Google Docs, which is free. Other great apps like Letters are Dropbox Paper (Free), Icedrive (Freemium), Google One (Freemium) and Twake (Freemium, Open Source).
Dropbox Paper is more than a doc—it’s a workspace that brings creation and coordination together in one place. KEEP EVERYONE ORGANIZED With Paper’s task management tools, you can assign to-dos, add due dates, and mention people—right from inside the doc.
Icedrive is a cloud storage, backup and file sharing service with browser, desktop and mobile apps. The Icedrive desktop application allows users to mount their cloud storage space as a real hard drive.
OffiDocs is a flexible and powerful platform that allows you to work online with desktop apps from everywhere at any time using only your web browser. OffiDocs provides you online desktop apps like LibreOffice, GIMP, Dia, ... through your web browser.
Remotely is a suite of essential business applications including chat, video conferencing, office apps and more which will help you work from anywhere. The suite includes full-featured Zoho tools like Cliq, Meeting, ShowTime, WorkDrive and many more.