Comparison

S4DX Samples vs Stopa

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

S4DX Samples

Read full description

Human samples are registered with help of the app directly during blood collection. The lab order is displayed to inform phlebotomists about sample types, number of samples, and pre-analytical advice. The user is immediately alerted if there are missing samples. The recording of additional information on the patient and/or sample in the app can be configured.

About

Stopa

Features
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Got a training plan from an AI chat or your coach in a spreadsheet? Stop retyping it. Paste it into Stopa, see your full calendar, and sync each workout to your Apple Watch in seconds, or to Garmin, COROS and Suunto through intervals.icu. No plan yet? Build one with the in-app coach - a conversation, not a template library. With your permission it reads your Apple Health history, so the plan starts from the training you have actually done. You review and edit every workout before anything reaches your watch. Built for self-coached runners, cyclists, and triathletes who want their plan on their wrist - not stuck in a PDF. WHAT IT DOES • Paste your plan from any AI chat or upload an Excel • Or create one with the in-app coach, grounded in your Apple Health data • See your full weekly and monthly training calendar • Workouts reach your Apple Watch on their own, via WorkoutKit • Garmin, COROS, Suunto and Wahoo through a connected intervals.icu account • Auto-pairs completed activities back to the plan via HealthKit • Compliance score after every session YOUR TRAINING DIARY Your whole history, not just the plan. Stopa reads your past sessions from Apple Health, so the diary is filled in from day one. Open any session for the full record: route map, splits, heart-rate zones, power - whatever your watch actually recorded. Add a note, or log a session by hand. STORIES Keep a stretch of training together - a weekend in the mountains, a training camp, a whole finished block - with its sessions, your notes and your photos. Share it as a card or a short film. FUELLING AND GUT TRAINING For long sessions and race day: carbohydrate, fluid and sodium per hour, built as a ladder that climbs across the block. Rehearse it in your long runs, tell Stopa how your stomach handled it, and the plan adjusts. Training intake only - no meal plans, no calorie counting, and nothing about body weight. GARMIN, SUUNTO, COROS AND MORE Your plan does not stop at the Apple Watch. Connect an intervals.icu account and it carries on to Garmin, Suunto, COROS, Wahoo and Zwift. Apple Watch stays the direct route. SEVEN LANGUAGES English, Czech, Spanish, German, French, Italian and Brazilian Portuguese - the app, the watch and the widgets. The plan reader speaks them too, so a Czech coach's spreadsheet is read in Czech, not translated first. WHY STOPA Most training apps lock you into an algorithm you cannot see, or charge $99+/year for what amounts to a calendar and watch sync. Stopa takes YOUR plan, in YOUR format, and gets it onto YOUR watch. And when you do want help writing one, the coach shows its work - every workout is yours to edit. SPORTS SUPPORTED Running, cycling, triathlon, swim. WATCH SUPPORT Native Apple Watch via WorkoutKit. Apple Watch Series 8 or later recommended. watchOS 10+ required. Garmin, COROS, Suunto, Wahoo and Zwift through a connected intervals.icu account. PRICING See week 1 of your own plan, in your paces, before you pay. Stopa Pro, monthly or yearly (founder price): watch sync, unlimited plans, coach chat, AI parser fallback, full training history, stories, fuelling plans, widget. The yearly plan starts with a 7-day free trial for new subscribers. The monthly plan starts the day you subscribe. Subscriptions renew automatically until you cancel in Settings. Made for athletes who think for themselves. stopa.app Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

S4DX Samples4 screens
Stopa4 screens

Verdict

The call

The clearest difference is in-app purchases: S4DX Samples at none against Stopa's 2. S4DX Samples also leads on iOS requirement (15.5 vs 26.0). Stopa's advantage is update cadence (monthly vs every 3 months). On price, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Stopa sells 2 in-app purchases, starting at $5.99 per month. S4DX Samples asks for nothing beyond the download.

UpkeepUpdate frequency

S4DX Samples ships an update every 3 months, Stopa monthly. The most recent releases landed on October 7, 2026 and October 16, 2026 respectively.

Scorecard3 real differences · 3 level
S4DX Samples versus Stopa: the parameters behind the verdict, then further details
ParameterS4DX SamplesStopa
PriceFreeFree
Update frequencyEvery 3 monthsMonthly — better
AdsNoNo
In-app purchasesNo — betterYes
DevicesiPhone, iPodiPhone, Apple Watch
Requires iOS15.5 — better26.0
Further details — not scored
Size80 MB23 MB
Age rating4+4+
DeveloperS4DX GmbHPeter Buchlak

In-app purchases

None

S4DX Samples

No in-app purchases

2 purchases

Stopa

Subscriptions2
  • Stopa Pro (Monthly)$5.991 Month
  • Stopa Pro (Annual)$49.991 Year

Questions

Is S4DX Samples free?
S4DX Samples is free to download, with no in-app purchases.
Is Stopa free?
Stopa is free to download, with in-app purchases available.
Do S4DX Samples or Stopa have ads?
Neither S4DX Samples nor Stopa shows ads.
Which is updated more often, S4DX Samples or Stopa?
S4DX Samples ships an update every 3 months, and Stopa monthly. Most recently, S4DX Samples was updated on October 7, 2026 and Stopa on October 16, 2026.

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