Question: Is there an AI tool that integrates with my macOS and iOS devices to provide context-aware assistance in any app?

WriteMage is a sophisticated AI-powered information retrieval system that natively runs ChatGPT on macOS and iOS. It's got a local chat history, customizable prompts and native integration with the iOS keyboard in all apps. At $10/month and up, it's a flexible tool for boosting productivity on multiple machines.

Another top contender is Impel, an AI sidekick designed for Mac users. It offers context-aware help, content summarization, task management and real-time Q&A. Impel's local data processing model means it's private and secure, making it a good choice for anyone who wants to get more done without sacrificing their privacy.

If you want a local AI assistant that works fully privately and offline, Private LLM is worth a look. The app supports several open-source LLM models and integrates with Siri and Shortcuts. It can perform tasks like grammar checking, summarization and text expansion, all with privacy and security in mind. As a one-time purchase, it's a relatively inexpensive and long-term option for personal use.