About mnemo

This app helps you understand how your days feel in hindsight — why some days fly by, while others feel long and rich.

How It Works

Every night you log how long the day felt on a 0–100 slider. Along with that, you can tag things like how many new places you went, new people you met, photos you took, task switches, and your mood.

These signals combine into something we call novelty. The more unusual and varied your day is compared to your personal baseline, the higher your novelty score.

What “Novelty” Means

Novelty isn’t just doing a lot — it’s about how different today was compared to your usual. For example:

  • If you normally go to 1 place but today you went to 4 → that’s novel.
  • If you usually meet nobody new but today you met 3 people → novel.
  • If you took way more photos than normal → novel.

Why Standard Deviation Matters

To measure “different,” the app looks at your average behavior and how much it normally varies (this is called standard deviation). Then it scores each day by how far it is from your personal norm (a z-score).

Example: If you usually visit 2 places a day (average) with a spread of ±1 (SD), then a day with 4 places = +2 SD = unusually novel.

Novelty Density

Your daily novelty score is the sum of all those z-scores:

Novelty = places + people + photos + task switches (+ mood variability)

Positive = richer, more unusual than normal. Negative = more routine.

Link to Felt Time

Research shows that richer, more novel days get encoded with more memory “chunks,” which makes them feel longer in hindsight. Routine days leave fewer traces and feel shorter.

The app compares your novelty density with your perceived length rating to see what really stretches time for you.

What You’ll See

  • Weekly Summary: average perceived length and how strongly novelty and time feelings correlated.
  • Top Drivers: which factors (places, people, photos, switches) mattered most for you this week.
  • Today’s Insight: plain-language feedback, e.g. “Today felt long because you met more new people than usual.”

Privacy

All data stays on your device. You can export it anytime as a JSON file if you want to analyze or share it.

Get Started →