PublicAPIs - Explore the largest API directory in the galaxy
Best Referral Programs - A curated directory of startup referral programs
API List - A collective list of APIs. Build something.
Viral Loops - Viral Loops is a viral and referral marketing platform to launch ranking competitions, sweepstakes, pre-launch and referral programs.
API for Product Managers - The A to Z of APIs for product managers
GrowSurf - Referral software for B2C, FinTech, and SaaS companies.