intoDNS - IntoDNS checks the health and configuration and provides DNS report and mail servers report.
Opta - Opta is a new kind of Infrastructure-As-Code framework designed for fast moving startups.
Dnsstuff - DNSstuff offers DNS tools, Network tools, Email tools, DNS reporting and IP information gathering.
Cal.com - Cal.com (formerly Calendso) is the open source Calendly alternative.
MxToolBox - All of your MX record, DNS, blacklist and SMTP diagnostics in one integrated tool.
Trriple mWallet - Easy & quick mobile payment platform