Q-Stats - Get free marketing insights for every question on Quora.

Rainmaker - Rainmaker allows you to make your Google Contacts better.

Site Rank Data - View historical rank information of websites via time series charts.

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.

HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.

dip - accountability groups for developers