Box - Box offers secure content management and collaboration for individuals, teams and businesses, enabling secure file sharing and access to your files online.
Invoice Ninja - Invoice Ninja is a free, open-source solution for invoicing and billing customers.
Google Drive - Access and sync your files anywhere
Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.
Dropbox - Online Sync and File Sharing
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.