Lanternwright

For the everyday stuffworking name

Pacing Companion

A web app that works offline, made to be usable on a bad day.

A pacing and symptom diary for people with post-exertional malaise, built to work on bad days.

Logging nothing and lying down is a completely valid way to use it.

Pacing Companion is an offline web app for people with ME/CFS, long COVID, POTS or other conditions where overdoing it costs days. Check in with one tap, plan the day around an energy envelope you set, see patterns in the log, and print a one-page summary to take to appointments.

What it does

  • A check-in that's manageable on a bad day. Energy, symptoms, a crash or flare mark and a note. Each one saves on its own tap, and “same as yesterday” is one tap too.
  • Plan around an energy envelope. You set the activity costs. Going over gets a gentle note, not a warning, and there are no streaks or scores.
  • Patterns, described plainly. What was logged, including each crash or flare and the three days before it.
  • A one-page summary for appointments. Print it, or save it as a PDF.
  • Easy to use when wiped out. Big tap targets, light, dark and high-contrast themes, bigger text, reduced motion, and full keyboard and screen reader support.
  • Offline, with no account. Back up to a JSON file, import or export CSV, or delete everything.

What it doesn't do

  • It never forecasts a crash or says why one happened.
  • Crash and flare days are marked by hand, not found by the app.
  • No wearable or heart-rate connections.
  • No cloud sync or cloud backup.
  • No AI insights or chatbots.

Who it's for

People with ME/CFS, long COVID, POTS or other conditions where overdoing it costs days, who want a calm, low-effort way to track and plan.

A few more screenshots

A headline reading “Pacing Companion: see what you logged, with no scores or streaks” beside a screenshot: Pacing Companion's Patterns screen for the last 30 days: days checked in, crash or flare days, days with activities logged, days over the energy envelope and average points done, with a note that patterns describe the entries and don't explain why anything happened.
Patterns describe what was logged, and don't try to explain it. The entries here are sample data.

Questions

Does it collect my data?
No. Everything entered stays in the browser's storage on your device. There's no account, no analytics and no third-party code, and it makes no network requests of its own.
Is it medical advice?
No. It's a personal diary and planning tool. Its patterns describe what was logged and never claim to know why something happened.
What if I can't pay for a supporter code?
Ask for a free one. No questions and no proof needed. Everything important is free without a code anyway.

What it keeps, and where

Nothing entered in it leaves the device, except a file you choose to save or share. The app doesn't make network requests of its own.

The full Pacing Companion privacy section

Runs on, and what it'll cost

Runs on
Web app for phone, tablet and desktop browsers. Installable, and works offline.
Cost
The core is free forever. An optional supporter code, pay what you want and one time, adds two extra themes and a day-by-day summary layout. A free code is available on request, with no questions asked.
License
MIT, so the code is open source.

Pacing Companion is a personal diary and planning tool. It is not a medical device and does not give medical advice.

A headline reading “Pacing Companion: one tap checks you in, even on a bad day” above a screenshot: Pacing Companion's Today screen on a phone, asking How is your energy right now? with five large buttons from Very low to Good, and Some selected. Click to try it
One invented day: the check-in, what it says back, and what happens when the plan is exceeded, which is a note rather than a warning. The day, the numbers and the costs in it are made up, nothing is kept and nothing is sent anywhere.

Pacing Companion has not launched yet. Rest costs nothing here, the same as in the app, and raising the envelope takes the day back inside it.