Discussion on:

10 must-try cloud tools for business

Great list

Google Apps is only $5 per user for Google Apps using your domain.

If you have a simple Google account you can use all the apps for free.

...Spanning (spanning.com) also offers backup/restore for Google Apps as well as some killer free tools like Undelete for Google Calendar (which is just what it sounds like), Admin Audit Log Viewer (keep track of changes in Google Apps accounts) and Stats for Google Drive (see how your Drive is being used). You can see how they stack up here: http://betanews.com/2013/02/09/spanning-takes-the-crown-for-google-apps-backup-services-review/

Another must have among cloud-based apps is digital signature tool provided by GroupDocs. Benefits of such a services expand when it is integrated seamlessly with a contract management system within an organization. My experience with GroupDocs Signature has been pretty good for a number of reasons but mainly because it is part of a complete suite of document management apps and streamlines the signature process easily. You should check it out as well and read more about it here:

http://cloudbasedwebapplicationsecurity.weebly.com/