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46 points dr-j | 1 comments | | HN request time: 0s | source

Hi HN! I’m Johan. I built Dlog, a journaling app with an AI coach that tracks how your personality, daily experiences, and well-being connect over time. It’s based on my PhD research in entrepreneurial well-being.

Edit: here's a video demo so you can see it before downloading: https://www.youtube.com/watch?v=74C4P8I164M - it's unvarnished but I'm told that's how people like it here :)

How Dlog works

- Journal and set goals/projects; Dlog scores entries on-device (sentiment + narrative signals) and updates your personal model.

- A built-in structural equation model (SEM) estimates which factors actually move your well-being week to week.

- The Coach turns those findings into specific guidance (e.g., “protect 90 minutes after client calls; that’s when energy dips for you”).

- No account; your journals live locally (in your calendar). You decide what, if anything, leaves the device.

The problem

- Generic AI coaches give advice without understanding your personality or context.

- Traditional journaling is reflective but doesn’t surface causal patterns.

- Well-being apps rarely account for individual differences or test what works for you over time.

What my research found (plain English)

In my PhD I modeled how Personality, Character, Resources, and Well-Being interact over time. The key is latent relationships: for example, Autonomy can buffer the impact of low Extraversion on social drain, while time/energy constraints mediate whether “good advice” is actionable. These effects are person-specific and evolve—so you need a model that learns you, not averages.

The solution

Dlog pairs on-device journaling analytics with an SEM that updates weekly. You get a running estimate of “what moves the needle for me,” and the Coach translates that into concrete suggestions aligned with your goals and constraints.

Early stories (anonymized from pilot users)

- A founder saw energy dips clustered after external calls; moving deep work to mornings reduced “bad days” and improved weekly mood stability.

- A solo designer’s autonomy scores predicted well-being more than raw hours worked; small boundary changes (client comms windows) helped more than time-tracking tweaks.

Tech & security

- Platform: macOS (Swift/SwiftUI). Data: local storage + EventKit calendar for entries/timestamps.

- Analytics: on-device sentiment + narrative features; SEM computed locally; weekly updates compare to your baseline.

- AI Coach: uses an enterprise LLM API for reasoning on derived features/summaries. By default, raw journal text does not leave the device; you can opt-in per prompt if you want the Coach to read a specific passage.

- Why 61 baseline variables? The SEM needs multiple indicators per construct (Personality, Character, Resources, Well-Being) to estimate stable latent factors without overfitting; weekly check-ins refresh those signals.

What I’ve learned building this

- Users value clarity with depth: concise recommendations paired with focused dashboards, often 5–10 charts, to explain the “why” and trade-offs.

- Cold start matters: a solid baseline makes the first week of insights credibly useful.

- Privacy UX needs to be explicit: users want granular control over what the Coach can read, per request.

I’m looking for feedback on:

- Onboarding (baseline survey and first-week experience)

- Coach guidance clarity and usefulness

- Analytics accuracy vs. your lived experience

- Edge cases, bugs, and performance

Download: https://dlog.pro

If you hit token limits while testing, email me at johan@dlog.pro

Background

PhD (Hunter Center for Entrepreneurship, Strathclyde), MBA (Babson), BComm (UCD). I study solo self-employment and well-being, and built Dlog to bring that research into a tool practitioners can use.

Note: The Coach activates after your first scored entry. If you haven’t written one yet, you’ll see a hold state—add a quick journal entry and it unlocks.

Appearance: On a few Macs the initial theme can render darker than intended. If you see this, switch to Light Mode as a temporary workaround; a fix is incoming.

Edit: For general users it's free for 14 days with 10K free tokens; then its 1.99 per month at the moment. However, for HN readers that DM me or email me with the email they register with, I'll give a free perpetual license so there's no monthly fee; and add 1 million tokens.

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thusjustin ◴[] No.45728244[source]
I love the vision. From what I can tell, you're building something that I think should exist and we have the technology for now. I think we need a place to put our 3, 5, 10 year goals, and some kind of process to keep us on track for that. And it's so personal, of course the LLM aspect needs to be local-only.

One concern I have is that I think I will need more than an empty "add Journal entry" nudge or prompt. I think I would want what a real coach would do/say. Something like, "How's the meditation/exercise/calling friends/making stuff going?"

replies(1): >>45731312 #
1. dr-j ◴[] No.45731312[source]
Thanks for the positive feedback! The LLM aspect is using enterprise API from openAI, their policy is to not train on user data; I've used it extensively for the last year with my own personal diary Dlog data; pretty dry stuff to be sure. However, I will be working on allowing the user to use their own on device models; at the moment running local models is too memory intensive for most users so I need to do this once the models are more compact. Apple have recently allowed developers to integrate AI through their foundation model LLM but the token window is too short, 8K only if I recall correctly; and the responses just aren't that useful. The technology will improve and trust in openAI's systems should increase; we're early days here, but for now the main mechanisms for LLM we are has to be the enterprise openAI; there's nothing better IMO. Another thing I am working on in the short term is mechanisms to anonymise content and approve the prompt before it is sent; as well as a simple toggle that when switched on removes that journal from being included in Coach analysis. Thanks again. If you DM or email me and let me know the email you used to sign up with Dlog then I'll send you a free perpetual license so DLog is free to use forever, excluding the AI tokens; and I'll give you 1 million free tokens. Have a wonderful day. Dr J.