Boomerang Respondable - Write perfect emails with Artificial Intelligence

Kosmo - Kosmo helps you automate your freelancing business. Including sending invoices, tracking time, managing projects and more.

Mailbutler - Mailbutler adds lacking functionality to email clients and increases your productivity

Harlow - Harlow helps freelancers get organized, save time, and look professional with automated invoicing, proposal templates, and much more—all from one centralized hub.

Boomerang for Gmail - Boomerang for Gmail is a Firefox / Chrome plugin that lets you take control of when you send and receive email messages.

Dubsado - Dubsado is flexible — it gives you 5 (now 6!) ways to add new leads. Best of all, 5 ways are automated.