Popular mood-tracking apps are often the worst offenders for privacy — they collect some of the most sensitive data a person generates. Here is the version that doesn't trade your mental health for an AD profile.
The business-model problem
A free mood tracker sells advertising against your mood data. Even "privacy-focused" ones often route to third-party analytics. Assume any free mental-health app is monetising your entries.
What to track
A single 1-5 score per day is enough. Daily trackers with 50 sliders produce false precision — nobody can reliably distinguish a 3.2 from a 3.4 on "energy" day-to-day.
Pair mood with context
Mood without context is noise. Mood + a one-sentence note ("slept poorly", "big launch tomorrow") gives the AI coach enough to spot patterns over time.
Monthly review beats daily alerts
Daily mood-tracking notifications make the anxious more anxious. Monthly reviews — "here is what your last 30 days looked like" — are useful. The cadence matters more than the fidelity.
Where on-device wins
Mood data is among the most personal data a human generates. Zero-knowledge or on-device are the only acceptable architectures. Anything less is a data breach waiting to happen.
About Sovereign — A privacy-first AI personal assistant that runs entirely on your iPhone. On-device LLM, zero-knowledge encryption, and a coach that learns from your own words. See how it works or visit the homepage.