OB ToolBox vs Bias Cure
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
OB ToolBox
This app offers a quick reference for essential medical values related to fetal growth, amniotic fluid, and Doppler indices. It includes calculators for preterm birth prediction, cesarean risk, and risk of stillbirth or miscarriage.
- Fetal growth reference values
- Estimated fetal weight calculator
- Amniotic fluid and Doppler indices
- Bishop score reference
- Preterm birth predictor
- Cesarean risk calculator
- Stillbirth and miscarriage risk calculators
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OB ToolBox provides a useful and quick reference values for fetal growth, estimated fetal weight, amniotic fluid and doppler indices, Bishop scores, preterm birth predictor, cesarean risk calculator, stillbirth calculator, miscarriage risk calculator, and more.
Bias Cure
This app helps medical professionals and patients understand the true probability of a condition after a test result. It clarifies complex statistical concepts, allowing for transparent communication of results and informed decision-making.
- Transparent sequential probability updating
- Individual 2x2 tables for test interpretation
- Visual probability trend graph
- Printable validation PDF with source citations
- Extensive library of conditions and tests
- Manual entry of custom diseases and tests
- Built-in help pages explaining Bayes' theorem
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Bias Cure supports transparent reasoning. It helps doctors and clinicians correctly interpret and communicate test results to their patients. The chances of having a particular cancer, given a positive test result, are not *at all* the same as the chances of getting a positive test result, given a person has that cancer. This app cuts through that confusion and provides the former number, the probability the patient *really* wants to know. Start with a possible "condition", add one or more test results, and watch the probability of having that condition update step by step. The app includes a an enlarged library of conditions and tests, but users also can enter any disease and diagnostic test manually and edit sensitivity and specificity values freely. The accuracy of the tests in the included library is backed by peer-reviewed research articles cited in the Validation Report, so users can go back to the original sources for more granular detail. Bias Cure includes transparent sequential probability updating, individual 2x2 tables for test interpretation, a visual probability trend graph, and a printable validation PDF that shows the intermediate steps behind the final result along with source citations. Built-in Help pages explain Bayes' theorem, the 2x2 table, and how to enter and interpret test data. Bias Cure is an educational and decision-support aid. It does not provide medical advice, does not replace clinical judgment, and should not be used as the sole basis for diagnosis or treatment decisions.
Screenshots
Verdict
The clearest difference is iOS requirement: OB ToolBox at 13.0 against Bias Cure's 17.0. On price, rating, ratings volume and update cadence 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
On the App Store both sit at effectively the same score — 5.0 for OB ToolBox against 5.0 for Bias Cure. Both are backed by a comparable volume of ratings — 2 and 1 respectively.
Both ship on a similar rhythm, roughly every 3 weeks. The most recent releases landed on September 21, 2026 and October 1, 2026 respectively.
| Parameter | OB ToolBox | Bias Cure |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) | 5.0 (1 ratings) |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 3 weeks | Every 3 weeks |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 13.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 56 MB | 2 MB |
| Age rating | 12+ | 17+ |
| Developer | Frederick Blair | Todd Doersch |
In-app purchases
OB ToolBox
No in-app purchases
Bias Cure
No in-app purchases






