Healthcare.gov - Since the healthcare law took full effect this year, HealthCare.

Intercom - Intercom is a customer relationship management and messaging tool for web businesses. Build relationships with users to create loyal customers.

Split Pic - Clone yourself and create collages!

Drift - A messaging app that helps you grow your business.

TravelInsurance.com - Travel insurance application.

C++ - Has imperative, object-oriented and generic programming features, while also providing the facilities for low level memory manipulation