Sites and apps similar to ExpressText.net include Telnyx. It's paid, but Google+ Hangouts API and Tellephant are free. Other options are Twilio, SMSAPI, Hilos by ActiveCampaign and iP.1 RESTful API. Email Marketing Services like ExpressText.net are a crowded field, with more than 25 alternatives for Android, iPhone, Mac, Windows and iPad.
Eagle Messaging offers voice messaging, text SMS service, Voicemail, IVR, chat, and more. Users can send 60 minutes of a recorded voice message. Cost-Effective, unlimited SMS service & all-inclusive price (Only $10) on a per-month subscription basis.
United Kingdom
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.
