Toggl - Toggl is an online time tracking tool. It features 1-click time tracking and helps you see where your time goes. Free and paid versions are available.

Stripe - Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce for online businesses of all sizes. Use Stripe’s payment platform to accept and process payments online for easy-to-use commerce solutions.

Harvest - Simple time tracking, fast online invoicing, and powerful reporting software. Simplify employee timesheets and billing. Get started for free.

Square - Square helps millions of sellers run their business-from secure credit card processing to point of sale solutions. Get paid faster with Square. Sign up today!

Hubstaff - Simple yet powerful employee work tracker with screenshots, timesheets, billing, in-depth reports, and more. Understand productivity issues and act on them.

QuickBooks Online - QuickBooks Online is a Cloud Accounting for small business that can be used on iPad, mobile phone or computer to do invoicing, billing, run reports, or even pay employees online.