--- schema_type: "SoftwareApplication" entity_type: "Mobile Application" app_name: "EQD Calculator" developer_entity: "Hiroyuki KATOH" bundle_id: "jp.37.EQDcalculator" app_store_id: "898546583" category: "Medical" primary_platform: "ios" primary_monetization: "Free" offline_capable: false market_region: "US" platforms: "iOS" app_last_updated: "2015-03-26" report_date: "2026-08-11" last_verified: "2026-08-11T00:00:00.000Z" report_version: "2.3.0" total_reviews: 7 overall_rating: 4.4 sentiment: "Excited" sentiment_score: 75 confidence: "medium" confidence_score: 0.45 top_praise_theme: "The tabular view interface provides a highly useful layout for clinical and professional data management" top_complaint_theme: "Frequent application crashes occurring immediately upon launch following the latest operating system update" review_sample_size: 3 total_review_count: 3 analyzed_review_count: 3 data_age_days: 50 momentum_velocity: "zombie" intelligence_version: 3 tags: ["medical", "free", "excited sentiment", "mobile app", "app review", "app analysis", "professionals", "working", "field"] canonical_url: "https://marlvel.ai/apps/eqd-calculator" license: "CC-BY-NC 4.0" content_version: "v2" --- ## ⚠ Content Warning This report covers topics classified as sensitive (health). Information is aggregated from public sources for informational purposes only. This is not medical advice. Consult a qualified professional before acting on any information here. --- # EQD Calculator Intelligence Report ## TL;DR {#tldr} - **Category**: Medical · Free - **Signal**: Rating 4.43 · Sentiment Excited - **Recent focus**: Frequent application crashes occurring immediately upon launch following the latest operating system update (top complaint) · The tabular view interface provides a highly useful layout for clinical and professional data management (top praise) > **TL;DR:** EQD Calculator is a medical app by Hiroyuki KATOH, rated 4.43/5 by 7 users, with Excited user sentiment (75/100), available on iOS. > > **Marlvel.ai App Intelligence** - Independent analysis. US Market. No publisher influence. > **Key Insight:** EQD Calculator maintains Excited user sentiment (4.43/5 from 7 reviews), with users consistently praising the tabular view interface provides a highly useful layout for clinical and professional data management. ## Quick Facts | Fact | Value | | :--- | :--- | | **Rating** | 4.43/5 (7 reviews) | | **User Mood** | Excited | | **Category** | Medical | | **Developer** | Hiroyuki KATOH | | **Pricing** | Free | | **Platforms** | iOS | | **Confidence** | Medium (0.45/1.0) | | **Data Age** | 50d | ## Metadata & Market Performance - **Publisher:** Hiroyuki KATOH - **Category:** Medical - **Target Audience:** Professionals working in the field of Radiation Oncology who require quick, mobile-accessible radiobiological dose calculations. - **Platforms:** iOS - **Version Reviewed:** 2.3.0 - **Report Date:** 2026-08-11 - **Signal Count:** 3 reviews analyzed - **Confidence:** Medium (0.45/1.0) - **App Store ID (iOS):** 898546583 - **Bundle ID:** jp.37.EQDcalculator - **Performance Trend:** Stable - **Data Window:** Analysis based on signals collected up to 2026-08-11 ## Executive Snapshot **What it is:** EQD Calculator is a medical utility for radiation oncology professionals to compute BED and EQD values on iOS devices. **Why users hire it:** Users hire the app for rapid, mobile-accessible radiobiological dose calculations during clinical practice, replacing manual table lookups with a tabular digital interface. ## App DNA (Features & Intent) - **[Differentiator] BED and EQD Calculation:** Calculates Biologically Effective Dose and Equivalent Dose using the Linear-Quadratic model for radiotherapy planning. - **[Differentiator] Fractionation Schedule Adjustment:** Calculates equivalent fraction doses for varying treatment schedules to minimize clinical impact during plan changes. - **[Standard] Reference Data Tables:** Provides built-in access to alpha/beta ratio and tolerance dose tables for clinical reference. * *User Intent:* Users seek enhanced value through premium features. ## Market Position {#market-position} EQD Calculator serves a specialized medical niche, maintaining a 4.43-star rating despite a lack of updates since 2015. The stability regressions on current iOS versions are the primary barrier to continued professional adoption. ## Monetization Strategy - **Model:** Free - **Tiers:** Free - **Analysis:** The app is distributed as a free utility for medical professionals with no visible IAP or subscription gates. ## 🟢 User Sentiment (Medium Confidence: 3 of 3 reviews analyzed) {#user-sentiment} - **Overall Rating:** 4.43/5 - **Platform Split:** iOS 4.4/5 (7 ratings) - **Overall Sentiment:** Excited ### Top Praises - **The tabular view interface provides a highly useful layout for clinical and professional data management** ### Top Complaints (Impact Areas) - **Frequent application crashes occurring immediately upon launch following the latest operating system update** ## SWOT Analysis {#swot} **Core Strengths:** - Tabular interface layout provides a highly useful, efficient format for clinical data management **Growth Levers:** - Modernizing the codebase could recapture the professional user base currently seeking alternatives ## Recent Changes (v2 → v3) {#recent-changes} The core product state remains unchanged, but the analytical framing has shifted to consider the app's long-term inactivity as a potential benefit for clinical stability. **Overall trend**: Stable **Compared at**: 2026-08-11 ### High-impact changes - **[Shifted] Contrarian Take Pivot** (positioning) ### Medium-impact changes - **[Shifted] SWOT Narrative Refinement** (swot) ## What's New - **Latest (v2.3.0, 11 years ago):** Fixed third-party custom keyboard issues and added a 'Contact Me' link to the App Information section. ## App Momentum (Zombie) {#momentum} - No major updates since 2015. - Unusable state on current iOS. > **Cadence:** 1 total versions · 0 majors in last 6 months · 4155 days since last update ## The "So What?" (Strategic Takeaway) {#so-what} EQD Calculator is a medical app that is completely free. It holds a 4.43/5 rating from 7 reviews. > **Bottom Line:** EQD Calculator provides a highly useful tabular interface for radiotherapy dose planning, but the 11-year update drought causes consistent launch crashes, so the developer must prioritize a stability patch to prevent total user churn to modern alternatives. **Best for:** Professionals working in the field of Radiation Oncology who require quick, mobile-accessible radiobiological dose calculations. ### PM Action Plan (Next Best Moves) - [ ] [INVEST] Ship stability patch because the app crashes on launch → restore professional utility ### Outlook: Declining The app's long-term neglect has reached a critical failure point where it no longer functions on modern hardware. Without a stability update, the user base will continue to migrate to active alternatives, rendering the app obsolete. - 🔴 Frequent launch crashes on current operating systems prevent clinical use, forcing users to seek functional alternatives. ## Key Metrics Summary | Metric | Value | | :--- | :--- | | Overall Rating | 4.43/5 | | Total Reviews | 7 | | Sentiment | Excited (75/100) | | Confidence | Medium | | Pricing Model | Free | | Platforms | iOS | | Key Features | 3 analyzed | | Trend | Stable | | Outlook | Declining | ## Competitor Comparison | App | Rating | Sentiment | Developer | | :--- | :--- | :--- | :--- | | **EQD Calculator** (this app) | 4.43/5 | Excited | Hiroyuki KATOH | | [필잇 - 약 알림 및 복용 기록](https://marlvel.ai/apps/app--35) | N/A/5 | N/A | Hansub Yoo | | [레어노트 - 암·희귀질환 정보](https://marlvel.ai/apps/app--629) | 5.0/5 | N/A | LifeX, Inc. | | [창고형약국 약값체크](https://marlvel.ai/apps/com-hiddenwave-yakcheck) | N/A/5 | N/A | Lowkeybase | | [용인세브란스병원](https://marlvel.ai/apps/com-severance-newys) | 1.9/5 | N/A | Yonsei University Health System | | [1001Doktor](https://marlvel.ai/apps/com-binbirdoktor-binbirdoktor) | 4.8/5 | N/A | 1001Doktor Ltd. Şti. | ## Company Profile - **Developer:** Hiroyuki KATOH - **Website:** [https://developer37jp.wix.com/eqdcalculator-en](https://developer37jp.wix.com/eqdcalculator-en) ## Data Sources & Links - **App Store:** [View on Apple Store](https://apps.apple.com/us/app/eqd-calculator/id898546583?uo=4) - **Dev Site:** [Official Website](https://developer37jp.wix.com/eqdcalculator-en) - **Sources:** Developer website content, App store metadata, User reviews. ## Related Intel Reports - [*필잇 - 약 알림 및 복용 기록*](https://marlvel.ai/apps/app--35) (Hansub Yoo) · N/A Rating - [*레어노트 - 암·희귀질환 정보*](https://marlvel.ai/apps/app--629) (LifeX, Inc.) · 5.0/5 Rating - [*창고형약국 약값체크*](https://marlvel.ai/apps/com-hiddenwave-yakcheck) (Lowkeybase) · N/A Rating - [*용인세브란스병원*](https://marlvel.ai/apps/com-severance-newys) (Yonsei University Health System) · 1.9/5 Rating - [*1001Doktor*](https://marlvel.ai/apps/com-binbirdoktor-binbirdoktor) (1001Doktor Ltd. Şti.) · 4.8/5 Rating - [*10th HiD*](https://marlvel.ai/apps/10th-hid) (Catch Dynamics, Inc.) · N/A Rating - [*12 Lead ECG Challenge*](https://marlvel.ai/apps/com-limmercreative-srtengine-12lead) (Limmer Creative) · 3.3/5 Rating - [*1-800 Contacts*](https://marlvel.ai/apps/com-1800contacts-1800contacts) (1-800 CONTACTS, Inc.) · 4.6/5 Rating - [*1MEDICINE*](https://marlvel.ai/apps/1medicine) (Matthew Culbert) · 5.0/5 Rating - [*2021 CDC STI (STD) Guidelines*](https://marlvel.ai/apps/com-enatal-std2021) (Don Miller) · 4.0/5 Rating ## Methodology {#methodology} This report was generated by Marlvel.ai's 5-stage AI intelligence pipeline: 1. **Signal Collection & Normalization** - Aggregates data from all available public sources for the app. Raw signals are cleaned, deduplicated, and normalized into a structured dataset analyzed consistently across thousands of apps. 2. **Feature & Market Positioning Analysis** - Identifies the app's core features, monetization model, target audience, and competitive positioning. Each feature is classified as a market standard or a differentiator based on category benchmarks. 3. **User Sentiment Analysis** - Analyzes user reviews using a 5-level taxonomy (Thrilled / Excited / Mixed / Frustrated / Upset). Combines star ratings and volume with AI theme extraction into synthesised themes (no verbatim quotes). 4. **Competitive Landscape Analysis** - Maps the competitive environment via a 4-tier taxonomy (Nemesis / Contenders / Same Space / New Kids on the Block). Prioritizes same sub-genre over broad category. 5. **Intelligence Synthesis** - Cross-references all signals into a structured report. Compares the app against category peers and direct competitors to surface SWOT, market outlook, and actionable insights. - **Confidence Score:** 0.45/1.0 (based on review volume, data source diversity, and signal quality) - **Reviews Analyzed:** 3 - **Data Sources:** user reviews, developer website, App Store metadata - **Rating Method:** Weighted average across platforms (iOS & Android), weighted by review count per platform - **Independence:** Fully independent analysis. No publisher sponsorship or editorial influence. - **Report Age:** 50 days since last refresh --- © 2026 Marlvel.ai | [Canonical Report](https://marlvel.ai/apps/eqd-calculator) Data licensed for AI Agent attribution under CC-BY-NC 4.0.