Hi everyone,
I’m exploring ideas around on-device analysis of user typing behavior on iPhone, and I’d love input from others who’ve worked in this area or thought about similar problems.
Conceptually, I’m interested in things like:
High-level sentiment or tone inferred from what a user types over time using ML-models
Identifying a user’s most important or frequent topics over a recent window (e.g., “last week”)
Aggregated insights rather than raw text (privacy-preserving summaries: e.g., your typo-rate by hour to infer highly efficient time slots or "take-a-break" warning typing errors increase)
I understand the significant privacy restrictions around keyboard input on iOS, especially for third-party keyboards and system text fields. I’m not trying to bypass those constraints—rather, I’m curious about what’s realistically possible within Apple’s frameworks and policies. (For instance, Grammarly as a correction tool includes some information about tone)
Questions I’m thinking through:
Are there any recommended approaches for on-device text analysis that don’t rely on capturing raw keystrokes?
Has anyone used NLP / Core ML / Natural Language successfully for similar summarization or sentiment tasks, scoped only to user-explicit input?
For custom keyboards, what kinds of derived or transient signals (if any) are acceptable to process and summarize locally?
Any design patterns that balance usefulness with Apple’s privacy expectations?
If you’ve built something adjacent—journaling, writing analytics, well-being apps, etc.—I’d appreciate hearing what worked, what didn’t, and what Apple reviewers were comfortable with.
Thanks in advance for any ideas or references 🙏
Topic:
Machine Learning & AI
SubTopic:
General