# Global Seismic Data vs Perci

The clearest difference is in-app purchases: Global Seismic Data at none against Perci's 6. Perci's advantage is update cadence (fortnightly vs every 8 months) and device support (3 vs 1). On price and ads there is nothing between them.

Both are free to download. Perci sells 6 in-app purchases, starting at $3.99 per month. Global Seismic Data asks for nothing beyond the download.

Global Seismic Data ships an update every 8 months, Perci fortnightly. The most recent releases landed on October 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Global Seismic Data | Perci |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.9 (16 ratings)](https://appshunter.io/ios/app/perci/id6449716815/reviews)** |
| Number of ratings | — | **16** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 8 months | **Fortnightly** |
| Monetization | — | Free with in-app purchases |
| Size | 26 MB | 73 MB |
| Requires iOS | 17.0 | **13.2** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 17+ |
| Developer | [Global Seismic Data NZ Limited](https://appshunter.io/developer/1469156236) | [Perci Ready LLC](https://appshunter.io/developer/1679170598) |

## What reviewers say

### Global Seismic Data

[App page](https://appshunter.io/ios/app/global-seismic-data/id1469156237)

**Features:** macOS Compatibility

**In-app purchases:** none


### Perci

[App page](https://appshunter.io/ios/app/perci/id6449716815)

Create personalized disaster readiness plans for your family with ease. This app generates comprehensive plans for various emergencies, including evacuation, home protection, and pet safety. Stay informed with extreme weather alerts and receive timely reminders to update your plans.

**Highlights:** Personalized readiness plans, Evacuation and home protection plans, Pet safety and school safety plans, Household needs and communication plans, Extreme weather alerts, Plan update reminders

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

**In-app purchases (6)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Solo Monthly | $3.99 | per month |
| Duo | $5.99 | per month |
| Family | $7.99 | per month |
| Solo | $39.99 | per year |
| Duo | $59.99 | per year |
| Family | $79.99 | per year |


## Frequently asked questions

### Is Global Seismic Data free?

Global Seismic Data is free to download, with no in-app purchases.

### Is Perci free?

Perci is free to download, with in-app purchases available.

### Do Global Seismic Data or Perci have ads?

Neither Global Seismic Data nor Perci shows ads.

### Which is updated more often, Global Seismic Data or Perci?

Global Seismic Data ships an update every 8 months, and Perci fortnightly. Most recently, Global Seismic Data was updated on October 26, 2026 and Perci on October 24, 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.*