The itch
Overthinking paralyzes action. Journaling apps hold your feelings, to-do lists hold your tasks, and nothing bridges the two: the moment where emotional clutter needs to become one small next step. I know this gap intimately. I've built enough coping systems over the years to open a small library.
Like a good PM, I wrote the product spec first. Then I realized the faster way to learn AI product-building was to stop speccing and start shipping.
What it is
Momentum is a working web app with three modes for three kinds of stuck:
- Can't Start? — You describe the task your brain won't begin; the AI streams five micro-steps so small they're basically insulting. Momentum through absurdity.
- Spiraling? — A big red panic button. No typing, no thinking: it streams cathartic physical actions to break the loop, with a "talk to someone?" path to real crisis resources. The design principle: in that state, every required decision is a failure.
- Too Many Things? — Dump all 47 things on your mind; the AI force-picks the three that matter today, with ruthless reasoning shown.
Every mode has selectable personalities: Snarky BFF (the default, obviously), Existential Hippie, and Supportive Coach. Because the same advice lands differently depending on who you need today. Some days you need a hug. Some days you need to be lightly bullied into opening the document.
What building it taught me that speccing couldn't
Prompt design is product design. The personality system is really a set of carefully constrained system prompts, and keeping "snarky" from drifting into "mean" turns out to be a guardrails problem (a fun one). Streaming changes the UX math too: perceived speed beats actual speed when someone is anxious. And honest scoping matters even when you're the only stakeholder. Panic mode deliberately hands off to human resources, because an app should not pretend to be a therapist.
What this shows
I don't just write PRDs about AI products. I ship them. Small, opinionated, and safe by design.