Landing Pages by Viral Loops - Easily create a landing page for your referral campaign ✌️
Interfacer - Collection of more than 200+ free design resources
Best Referral Programs - A curated directory of startup referral programs
Facebook Design Resources - A collection of free resources made by designers at Facebook
Rewardful - All-in-One Affiliate Management Software for SaaS
Freebiesbug - Collection of the best free web design resources.