MailChimp - MailChimp is the best way to design, send, and share email newsletters.
Rainmaker - Rainmaker allows you to make your Google Contacts better.
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
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.
GetResponse - Email marketing from GetResponse. Send email newsletters, campaigns, online surveys and follow-up autoresponders. Simple, easy interface. FREE sign up.
dip - accountability groups for developers