# GRAPPA App vs Derm Calculator

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.

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.

## The numbers

| Metric | GRAPPA App | Derm Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (2 ratings)](https://appshunter.io/ios/app/grappa-app/id1346646781/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/derm-calculator/id6444107895/reviews) |
| Number of ratings | **2** | 1 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 3 months** | Every 6 months |
| Monetization | Free | Free |
| Size | 64 MB | 58 MB |
| Requires iOS | 13.0 | **12.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 17+ | 12+ |
| Developer | [Group for Research and Assessment of Psoriasis and Psoriatic Arthritis](https://appshunter.io/developer/1346646780) | [RISETECH (PRIVATE) LIMITED](https://appshunter.io/developer/1611879875) |

## What reviewers say

### GRAPPA App

[App page](https://appshunter.io/ios/app/grappa-app/id1346646781)

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.

**Highlights:** Psoriatic arthritis and psoriasis assessment, Disease severity calculators (MDA, PASI, BSA), Patient-completed questionnaires (PsAID, PEST, HAQ), Multilingual questionnaire support, Access to GRAPPA resources

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


### Derm Calculator

[App page](https://appshunter.io/ios/app/derm-calculator/id6444107895)

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.

**Highlights:** Comprehensive scoring systems, Clinical reference, Research tool, Dermatology focus

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is GRAPPA App free?

GRAPPA App is free to download, with no in-app purchases.

### Is Derm Calculator free?

Derm Calculator is free to download, with no in-app purchases.

### Which has better reviews, GRAPPA App or Derm Calculator?

GRAPPA App and Derm Calculator are both rated 5.0 out of 5 on the App Store, from 2 and 1 ratings respectively.

### Do GRAPPA App or Derm Calculator have ads?

Neither GRAPPA App nor Derm Calculator shows ads.

### Which is updated more often, GRAPPA App or Derm Calculator?

GRAPPA App ships an update every 3 months, and Derm Calculator every 6 months. Most recently, GRAPPA App was updated on July 19, 2026 and Derm Calculator on September 18, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*