nizu.io is described as 'NIZU API is a market of application programming interfaces for WhatsApp, VIN Decoding, Trello, Rocket Chat, email etc among others'. There are six alternatives to nizu.io for Online / Web-based, SaaS and Self-Hosted solutions. The best alternative is Twilio, which is free. Other great apps like nizu.io are MessageBird (Paid), SendSMSGate (Paid), Infobip (Freemium) and Amio (Freemium).
Twilio is a web-service API that lets you use your existing web languages and skills to build voice and SMS applications. We focus on building a simple, powerful, pay-as-you-go communications platform so that you can focus on what you do best.
International Communication Platform as a Service (CPaaS) provider with zero-hop connectivity to telecoms globally. It supports all major mobile communication channels, like SMS, email, WhatsApp, Viber, voice, video and more, over API and web UI.