Waitlist API - Quick and easy waitlist with built in referral.
SerpClix - SerpClix is a click exchange network used to send more real clicks to your Google SERP. You can click to earn money or buy clicks to rank higher on Google.
LaunchList - Create waitlist with referral for your product launch
Honeygain - Time flies when you’re making sweet money. Simply download the app, turn it on, and earn!
Waitlisty.io - Build excitement for your product by embedding a simple form into your website. Signups will receive a referral code to share with their friends. The more codes they share, the more they climb your waitlist.
21 Lists - Send and receive targeted, paid microtasks