GRAPPA App vs Derm Calculator
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
GRAPPA App
This medical application aids in the assessment of patients with psoriatic arthritis and psoriasis. It provides tools to calculate disease severity scores and includes patient-completed questionnaires in multiple languages. Access to GRAPPA resources is also available.
- Psoriatic arthritis and psoriasis assessment
- Disease severity calculators (MDA, PASI, BSA)
- Patient-completed questionnaires (PsAID, PEST, HAQ)
- Multilingual questionnaire support
- Access to GRAPPA resources
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This app from GRAPPA (Group for Research and Assessment of Psoriasis and Psoriatic Arthritis) is designed to support the assessment of patients with psoriatic arthritis and psoriasis. It allows users to calculate a patient’s MDA and assess skin disease (using either PASI or BSA) through specially designed calculators. The app also includes PsAID, PEST and HAQ questionnaires which can be completed directly by patients in a range of languages and a selection of slides from the GRAPPA resources. Visit http://www.grappanetwork.org/ to find out more about GRAPPA.
Derm Calculator
This app consolidates dermatology clinical and research scoring systems for easy access. It serves as a reference tool for medical professionals and researchers in the field of dermatology.
- Comprehensive scoring systems
- Clinical reference
- Research tool
- Dermatology focus
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A comprehensive platform that features all relevant dermatology clinical and research scoring systems in one place. Disclaimer: Users should seek a dermatologist's advice before making any medical decisions based on the findings in this application.
Screenshots
Verdict
GRAPPA App and Derm Calculator are too close to call on the numbers: across 9 compared parameters — price, rating, ratings volume and update cadence among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.
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 GRAPPA App against 5.0 for Derm Calculator. Both are backed by a comparable volume of ratings — 2 and 1 respectively.
GRAPPA App ships an update every 3 months, Derm Calculator every 6 months. The most recent releases landed on July 19, 2026 and September 18, 2026 respectively.
| Parameter | GRAPPA App | Derm Calculator |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (2 ratings) | 5.0 (1 ratings) |
| Number of ratings | 2 — better | 1 |
| Update frequency | Every 3 months — better | Every 6 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 13.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 64 MB | 58 MB |
| Age rating | 17+ | 12+ |
| Developer | Group for Research and Assessment of Psoriasis and Psoriatic Arthritis | RISETECH (PRIVATE) LIMITED |
Customer experience
GRAPPA App
Derm Calculator
In-app purchases
GRAPPA App
No in-app purchases
Derm Calculator
No in-app purchases
