Twilio - Brings voice and messaging to your web and mobile applications.
Microsoft Teams - Microsoft Teams provides the enterprise-level security, compliance and management features you expect from Office 365, including broad support for compliance standards, and eDiscovery and legal hold for channels, chats, and files.
Bandwidth - Bandwidth offers SIP trunking, Emergency communications, and Voice & Messaging APIs.
Airtable - Airtable works like a spreadsheet but gives you the power of a database to organize anything. Sign up for free.
Nexmo - Nexmo is a simple two way SMS API with global reach and wholesale rates
Creativity 365 - Cross-device content creation suite