Evernote and GDrive are my two favourite Cloud tools. Unfortunately, either of them currently has the official client. But there are a couple unofficial clients which work well in Ubunu. Nevernote and Everpad are for Evernote, Grive and Insync are for GDrive.
Personally, I prefer Nevernote and Grive.
How to install Nevernote in Ubuntu:
sudo add-apt-repository ppa:vincent-c/nevernote
sudo apt-get update
sudo apt-get install nixnote
How to install Grive in Ubuntu:
sudo add-apt-repository ppa:thefanclub/grive-tools
sudo apt-get update
sudo apt-get install grive-tools
Jackie Chen's IT Workshop 