Quip - Quip is the modern productivity suite that simplifies your life and helps your team get work done faster.
Smallpdf - PDF document management and conversion suite
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.
iLovePDF - Free online PDF tool set
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.
Kingshiper Image Compressor - With Kingshiper Image Compressor, you can easily compress, optimize and reduce jpg, jpeg, png, svg and gif file to a smaller size in seconds.