Nova Inbox - Personalize emails in seconds, right from your inbox
SendX.io - SendX (https://sendx.io) provides remarketing and retargeting tools for web businesses. You can use popups, landing pages, email, web push notification, automation workflows and FB / Google retargeting to drive more revenue.
Dynamically Personalized Emails by QGraph - Hyper-personalized emails for E-commerce
Gmail Mail Merge - Send personalized emails with attachments
Mailblast - Email marketing on a budget using Amazon SES
InboxSDK - First usable API to write Gmail Apps for 1B active users