The Qt development framework presents a rich set of tools for the creation of cross platform applications with an advanced UI. The framework supports all popular desktop and mobile operating systems and shares 5th-6th place in a global non-official rating of all cross platform and hybrid toolchains for desktop and mobile development.
The two main standards currently are Apple’s iBeacon and Google’s Eddystone. Also there are some alternatives like URIBeacon and ALTBeacon but it does not seem that these alternatives are particularly popular now.
One of the most common ways to make an application that reacts to natural language is to use Amazon’s NLU service Alexa. Alexa is a well known and widely used platform that analyzes a natural language, recognizes commands and passes them to an application.
The IoT segment, and wearable devices as an important part of it, now urgently needs to unify protocols and standards for communications. Today there are 10+ solutions that claim to be good solutions for the Internet of Things space. But Bluetooth Low Energy (BLE) is the most likely to remain as the de-facto standard for data transfer for wearable devices that aim to be energy efficient.