Comparison

Breath Diary vs Kidneybook

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

Head to head
About

Breath Diary

Features
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Breath Diary helps you record daily wellbeing, practice exercises and review changes in fitness. The app and every feature are free, with no ads, in-app purchases or subscriptions. A SEATED EXERCISE COURSE The standard course takes about five minutes, from breathing through gentle movements to rest. Follow the illustrations, short captions and voice guidance. Results are saved automatically at the end. Rest, resume, skip or finish early. Review an interrupted practice session before resuming it. 16 EXERCISES Includes pursed-lip breathing, shoulder raises, chest stretches, knee extensions, walking and more. Change the exercises, order, repetitions and durations. Default amounts are a guide. Follow your healthcare professional's instructions when provided. JAPANESE AND ENGLISH Use the interface, instructions and captions for all 16 exercises, fitness checks, reminders and visit summary in Japanese or English. Guidance uses an installed Apple voice matching the app language. Choose automatic, male-preferred or female-preferred voices and preview the available voice in Settings. If your preferred voice is unavailable, another voice in the same language is selected. If none is available, follow the on-screen instructions. Names and notes you enter are not translated. YOUR DAILY DIARY Record wellbeing, breathlessness, cough, sputum, medication, steps and notes. Blank entries, None and 0 remain distinct. Optional Apple Health integration reads step counts only. Manually entered steps, including 0, take priority. The diary and exercises remain usable without HealthKit access. FITNESS CHECKS Record the time, results and conditions of a 30-second chair stand or 6-minute walk. Follow healthcare instructions and have the necessary supervision. Enter a measured walking distance or calculate it from a known one-way course length and lengths completed. The app does not measure distance using a camera or AR. Previous AR records remain available as reference values. REVIEW AND SHARE Use the calendar and 7-, 30- or 90-day views. Compare completed checks performed with the same method and conditions. Share a visit summary in the app language. For compatibility, CSV exports keep the existing Japanese column names, values and date format. You choose the recipient or save location in the system share sheet. Records are stored on your device; no account is needed. There is no app-provided cloud sync, advertising or tracking. OS backups may include app data according to your settings. Core features work offline; opening sources, support or the privacy policy requires a connection. Supports iPhone, iPad, text-size settings, VoiceOver and Dark Mode. The app does not diagnose or treat conditions or guarantee exercise effects or measurement accuracy. If you feel different from usual, do not push yourself; follow the plan agreed with your healthcare professional. Guided repetitions count movements shown on screen, not detected body movements. SUPPORT misterdevelop.support@gmail.com https://misterpepo.github.io/misterdevelop-support/

About

Kidneybook

Features
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Your lab reports, as one line. Kidneybook is a simple log for chronic kidney disease. Type in the creatinine and eGFR values you get at each appointment and years of history become clear at a glance. No sign-up. No ads. Everything stays on your device. β–  16 lab items, all free Creatinine, eGFR, urea nitrogen, uric acid, urine protein, urine albumin, potassium, phosphorus, sodium, calcium, albumin, hemoglobin, LDL cholesterol and more. Add your own items when your clinic measures something that isn't here, and reorder or hide the ones you don't use. β–  Work back through the folder Start with your most recent report, then use Save and go to the previous test β€” the date steps back by your appointment interval. You can enter years of old reports in order, up to 20 years back. β–  The difference from last time, and nothing more Each value shows the change from the previous test with a + or βˆ’. There is no colour-coding, no reference ranges, no "abnormal" flag, and no eGFR calculation. It is your record, not a judgement. β–  Daily weight and blood pressure, if you want them Turn on the Daily tab to record weight and blood pressure at home, morning and evening. Leave it off if you only want lab values. β–  One page for the clinic The last 12 tests as a single landscape table (Pro). Free: all 16 lab items, adding and reordering items, entering past tests, and the last 90 days of the charts. Pro (a one-time purchase, no subscription): charts over all time, the clinic PDF, CSV export, and managing other people. Note: this app is a log for your lab results. It does not diagnose, treat, or provide medical advice; it makes no comparison against reference ranges and does not calculate eGFR. Always talk to your doctor about your values, how you feel, and your treatment.

Screenshots

Breath Diary4 screens
Kidneybook3 screens

Verdict

The call

The clearest difference is update cadence: Kidneybook at every 2 weeks against Breath Diary's monthly. On price, ads, in-app purchases and device support there is nothing between them.

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

CostPrice Β· In-app purchases Β· Ads Β· Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Breath Diary ships an update monthly, Kidneybook every 2 weeks. The most recent releases landed on October 30, 2026 and October 31, 2026 respectively.

Scorecard1 real difference Β· 5 level
Breath Diary versus Kidneybook: the parameters behind the verdict, then further details
ParameterBreath DiaryKidneybook
PriceFreeFree
Update frequencyMonthlyEvery 2 weeks β€” better
AdsNoNo
In-app purchasesNoNo
DevicesiPhone, iPad β€” betteriPhone
Requires iOS18.017.0 β€” better
Further details β€” not scored
Size56 MB12 MB
Age rating17+12+
Developeryuuki iwamotoRAINBOW TREE LLC

In-app purchases

None

Breath Diary

No in-app purchases

None

Kidneybook

No in-app purchases

Questions

Is Breath Diary free?
Breath Diary is free to download, with no in-app purchases.
Is Kidneybook free?
Kidneybook is free to download, with no in-app purchases.
Do Breath Diary or Kidneybook have ads?
Neither Breath Diary nor Kidneybook shows ads.
Which is updated more often, Breath Diary or Kidneybook?
Breath Diary ships an update monthly, and Kidneybook every 2 weeks. Most recently, Breath Diary was updated on October 30, 2026 and Kidneybook on October 31, 2026.

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