Amio is described as 'Simple API for complex messaging world Implement multiple messengers into your software with single and powerful API'. There are nine alternatives to Amio, not only websites but also apps for SaaS and Self-Hosted solutions. The best alternative is Twilio, which is free. Other great sites and apps similar to Amio are MessageBird (Paid), nizu.io (Paid), SendSMSGate (Paid) and ShoutOUT (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.
WhatsApp is a popular messaging platform around the globe. With Maytapi you can send and receive messages from WhatsApp using simple HTTP requests. Integrate your marketing or business platform (Shopify, Woocommerce, CRM ets.) to WhatsApp easily.