SendGrid is a cloud-based SMTP provider that allows you to send email without having to maintain email servers. SendGrid manages all of the technical details, from scaling the infrastructure to ISP outreach and reputation monitoring to whitelist services and real time analytics.

Developed by Intuit, QuickBooks is an accounting software whose products provide desktop and online accounting applications as well as cloud-based ones which can process bills and business payments. QuickBooks is mostly targeted at medium and small businesses. Ease of use and reporting functionality makes QuickBooks popular among these users.

The ultimate messaging app for business. Slack transforms the way organizations communicate by bringing people together to work as one unified team.