IOS and AI/Machine Learning
Checkout this Developer Page from Apple. It gives you great idea around what can you accomplish in IOS device.
https://developer.apple.com/machine-learning/
Apple gives you capabilities to use Vision, NLP based applications that can use data generated by device's native abilities like camera. A Developer has access to powerful features through CoreML framework to build feature rich/powerful apps that can run on the device itself, using hardware capabilities apple has incorporated into latest ios devices. Imagine building speech recognition or image recognition type apps, that doesn't need to go back to cloud to do the processing, thus utilizing computing power in the device itself and can work offline.
Vision
You can easily build computer vision machine learning features into your app. Supported features include face tracking, face detection, landmarks, text detection, rectangle detection, barcode detection, object tracking, and image registration.
Natural Language Processing
The natural language processing APIs in Foundation use machine learning to deeply understand text using features such as language identification, tokenization, lemmatization, part of speech, and named entity recognition