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.
Avochato - Text messaging for your business.
Nova Inbox - Personalize emails in seconds, right from your inbox
Message Me - Website to create your contact business card
Mailblast - Email marketing on a budget using Amazon SES
Slack with your Users - Speak to your app's users entirely within Slack