Waitlist API - Quick and easy waitlist with built in referral.
ViralSweep - Grow your fans and increase sales with sweepstakes and giveaways.
LaunchList - Create waitlist with referral for your product launch
Retweet Picker - Retweet Picker is an online tool that is helping you to select the random winner from Twitter for the giveaways.
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.
Retweet Pick - Retweet Pick is a random name generator for Twitter giveaways via generating a winning name from the list.