Luupro - Get social about the projects you're working on!
Envisage - Inject contextual help on your site. Point and click style.
Waitlist API - Quick and easy waitlist with built in referral.
Codesign.io - Visual feedback on everything
Landing Pages in MailChimp - Easy to build, custom landing pages for free
Product Fit - Measure product/market fit in app with your users.