Sumo - Free tools to grow your email list.
Proof - Website conversion rate optimization and visitor monitoring
OptinMonster - OptinMonster helps to convert abandoning website visitors into subscribers and customers.
Picreel - Recover abandoning visitors and turn them into 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