TL;DR - The Apple Fitness app and Samsung Health both do a fine job with distance, time, average heart rate, and SWOLF. - What they don't show you well is what worked and what fell apart inside a single session. - FINNS fills exactly that gap — through time-axis multi-charts and cumulative pattern analysis.
What the Stock Watch Apps Get Right
Let's start with what's honest. Stock swim tracking on both watches is already very good.
- Apple Watch — automatic stroke detection, automatic lap recognition through turn detection, calories, heart rate, SWOLF. The Fitness app's per-day trend view is clean.
- Galaxy Watch — distance by stroke, average heart rate, calories, even SpO2. Samsung Health surfaces monthly and yearly summaries.
If you're a once-or-twice-a-week casual swimmer, this is enough. There's no real reason to install another app.
But — Can They Answer These Questions?
Once you start taking swimming seriously, certain questions show up on their own.
Q1. "My 4th 100m in today's 800m freestyle felt awful. Can I see it in the data?"
- Stock watch: You get the 100m lap time. What happened to your heart rate inside that 100m is not visible.
- FINNS: Heart rate, pace, and stroke are stacked on the same time axis. Tap the 4th 100m segment with your finger and the heart rate, SWOLF, and stroke count at that exact moment all surface together.
Q2. "Has my breaststroke SWOLF improved over the last three months?"
- Stock watch: Only daily average SWOLF. To split it by stroke you'd have to export to a spreadsheet.
- FINNS: SWOLF trend per stroke is on the default screen. A best-so-far step line marks the moment each PB landed, so "this is where I broke through" is one glance away.
Q3. "How different is intensity between a coached lesson and a free swim?"
- Stock watch: No distinction exists. Everything is just "Swim."
- FINNS: Register your lesson schedule and auto-classification kicks in. Average heart rate, distance, and SWOLF show up separately for lesson vs. free swim labels.
Q4. "How long did I actually spend in Zone 3 or above?"
- Stock watch: Heart rate zone distribution is great for running and cycling, weaker for swimming. Galaxy Watch in particular drops HR samples during parts of a swim, which makes the distribution hard to compute fairly.
- FINNS: Z1–Z5 distribution is shown as a card. Android v2.0 includes correction for dropped HR segments on Galaxy Watch.
Q5. "How many total kilometers did I freestyle this year?"
- Stock watch: Cumulative distance by stroke is not aggregated as its own metric.
- FINNS: Per-stroke cumulative distance is wired into the medal system. "12km left until the 100km Freestyle medal" shows up directly.
The Real Limit — Watch Apps Are Recorders, Not Analyzers
Stock watch apps do a fine job of summarizing a single session. That is their job.
But what a swimmer actually wants tends to come down to two things.
- Looking inside a session — slicing today's swim along the time axis to see what worked and what broke down.
- Connecting sessions to each other — comparing to last week, last month, this time last year, and seeing where you stand.
Both require the raw workout data to be reprocessed. The stock apps don't go that far. That's the actual limit — not a bug, not a flaw. The watch apps were designed for something different.
What FINNS Fills In — Same Data, Different Screen
FINNS does not tell you to buy a new watch. It takes the exact data your Apple Watch or Galaxy Watch already produces and renders it differently.
The same data, redrawn four ways
- Timeline mode — unfold a single session across five channels
- Trend mode — weekly, monthly, yearly, and all-time trends separated by stroke
- Pattern mode — time-of-day and weekday patterns, lesson/free distribution, heart-rate zone distribution, all on one screen
- PB mode — personal bests by distance × stroke, with timestamps for each update
Where the watch data has gaps, we say so
- HR gaps during swims on Galaxy Watch are interpolated, but the interpolated section is visually marked so you know it isn't measured.
- If Apple Watch misidentifies a stroke, you can correct the stroke at the session level.
- What the watch didn't measure, we don't invent. Z1–Z5 distribution is computed only across segments where real HR samples exist.
So Who Is FINNS For?
Casual swimmers don't need to be talked into this. But if two or more of these apply to you, give it a try.
- [ ] You swim at least twice a week
- [ ] You want PBs split by stroke
- [ ] You're part of a lesson, a Masters club, or a swim group
- [ ] You want to verify whether today's swim was recovery or intensity, in numbers
- [ ] Medals and badges work as motivation for you
- [ ] You want your watch data to stay on your device, not in someone's cloud
Coming Up Next
The next post walks through FINNS's signature feature — the five-channel multi-chart — with real screen examples. "How do I actually read one screen?" is the question we get most often.
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