Sumo - Free tools to grow your email list.
OptinMonster - OptinMonster helps to convert abandoning website visitors into subscribers and customers.
Poptin - Create engaging and high converting website pop ups and contact forms in minutes. With Poptin, you get access to a feature-packed conversion rate optimization toolkit that converts more website visitors into email subscribers, leads, and customers.
OptiMonk - OptiMonk is the most powerful Onsite Retargeting platform, that helps you increase the conversion rate of your site, and get more leads by recovering lost visitors.
GetSiteControl - Website popup builder & email marketing suite for ecommerce
Sleeknote - Set up lead capture forms on your website in minutes. No coding required. Sync your new email leads with your favorite email service provider. Try for free.