Wassenger - WhatsApp API made simple for developers and businesses
Zapier - Connect the apps you use everyday to automate your work and be more productive. 1000+ apps and easy integrations - get started in minutes.
Voiceflow - Build voice apps in your browser without coding
Integromat - Tool for workflow automation
Picky Assist - Your Andriod Phone As A Gateway to Automate WhatsApp, SMS & Calls
Microsoft Flow - Similar to IFTTT and Zapier you can create automated tasks based on APIs from various services.