TestFlight - iOS beta testing on the fly.
Usetiful - Fight user churn with great user onboarding. Interactive product tours and smart tips significantly improve your user retention.
Boombox.io - iOS devs rejoice! Embeddable HTML and hosted TestFlight beta sign-up forms.
User Onboarding - Onboarding teardowns of popular sites/services
Applivery - Mobile Apps distribution system for Continuous deployment, Beta testing, Feedback, Bug reporting & Enterprise App distribution.
UserGuiding - User onboarding made easy, for less. Create product walkthroughs in a couple of clicks, without breaking the bank.