TemplateMo - TemplateMo is a great place to get bootstrap templates from your website, which are all HTML5 supported with CSS layout.
Rewardful - All-in-One Affiliate Management Software for SaaS
Ethereal by HTML5 UP - A fully responsive side-scrolling one-page HTML5 template
Best Referral Programs - A curated directory of startup referral programs
UIdeck - Landing Page HTML Templates and UI Kits
Landing Pages by Viral Loops - Easily create a landing page for your referral campaign ✌️