OptinMonster - OptinMonster helps to convert abandoning website visitors into subscribers and customers.
Hunter - Find all the email addresses related to a domain
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.
Albacross - The world's first free B2B Lead Generation Network. Albacross help companies master their B2B digital marketing with Lead Generation and targeted marketing
GetSiteControl - Website popup builder & email marketing suite for ecommerce
Upscribe - Embeddable lead generation forms for Medium