There's an on device LLM that is packaged in iOS, iPadOS and macOS 26 (Tahoe) [1]. They even have a HIG on use of generative AI [2]
Something like half of all macs are running macOS 26 [3] already, so this could be the most widely distributed on-device LLM on the planet.
I think people are sleeping on this, partly because the model is seen as under powered. But I think we can presume it won't always be so.
I've just posted a Show HN of app for macOS 26 I created that uses Apple's local LLM to summarize conversations you've had with Claude Code and Codex. [3]
I've been somewhat surprised at the quality and reliability of Apple's built-in LLM and have only been limited by the logic I've built around it.
I think Apple's packaging of an LLM in its core operating systems is actually a fast move with AI and even has potential to act as an existential threat to Windows.
[1] https://developer.apple.com/videos/play/wwdc2025/286/
[2] https://developer.apple.com/design/human-interface-guideline...