Principles
Things the app structurally can't do.
Not settings you switch off. Decisions made in the schema, where a future feature can't quietly undo them.
Show real data, even when it's unflattering
Results are marked clearly, weight change is visible, and a week that went backwards looks like a week that went backwards. Someone deciding what to change needs the actual information, not a softened version of it. This is the principle the others exist to keep honest — the rest limit what Swell is allowed to conclude, not what it's allowed to show you.
No single life score
Health, money and mind are never combined into one number. A blended figure lets a good month in one place hide a bad one somewhere else, which is exactly the information you opened the app for.
Absence is a gap
A day with no entry is drawn as nothing. Not a zero, not a dip, not a line interpolated between the days either side. Charts stop and restart, because a guess plotted next to a measurement stops you trusting either.
Adding something new can't lower what you had
Pillar figures average only the sub-areas you've actually started. Turning on Meditation for the first time doesn't punish you for a month of not meditating.
Quiet weeks cost you slowly
Scores climb quickly when you're entering things and drift down gently when you're not, toward a floor they never fall through. A quiet fortnight shouldn't wipe out a good quarter.
Personal bests are facts, not targets
Your heaviest set reads as “heaviest yet”. There's no “3kg off your PR”, no bar filling toward a past session, and no state that calls a workout incomplete because you planned more than you did.
Your body isn't a denominator
Bodyweight exercises record reps and any weight you added on top. Body mass has no column to live in, so no metric can quietly divide your performance by how heavy you are.
Targets are computed, never invented
Calorie and weight targets come from a standard formula — Mifflin–St Jeor — with the deficit capped as a share of maintenance, the weekly rate of change capped, an absolute floor the app won't go below whatever the goal, and a protein floor kept even in a deficit. Language explains the number; it never chooses it. You pick a pace and Swell tells you the date it implies, rather than taking a date and inventing a pace nobody could sustain. Weight itself carries no streak and no score — it moves on water, salt and timing, and streaking it would punish noise you didn't cause.
Plans cite their sources
Every task in a weekly plan names the entries it came from. A task that can't do that doesn't get written. This is what keeps plans specific rather than filling space with “read more” and “reflect daily”.
Code does the arithmetic
Totals, averages, streaks, annualised costs and category sums are all computed the same way every time. Language handles the parts that are language — naming a merchant, describing a pattern, writing the sentence.
Estimates say they're estimates
Anything modelled rather than measured is labelled, given a range, and shows the assumptions it used. A projection is never printed with the same confidence as a figure you entered.
No products, no picks
Swell shows you where your money went and what it repeats. It doesn't recommend accounts, choose investments, or tell you what to do with what's left.
Held to, not advertised
Find one broken? That's a bug.
If you find somewhere Swell breaks one of these, it's worth writing in about.