# Birdathon vs Stoichiometry Pro

The clearest difference is price: Birdathon at Free against Stoichiometry Pro's $3.99. Stoichiometry Pro's advantage is in-app purchases (none vs 4). On update cadence, ads, device support and iOS requirement there is nothing between them.

Birdathon is free to download; Stoichiometry Pro costs $3.99 up front. Birdathon sells 4 one-off in-app purchases. Stoichiometry Pro asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on September 19, 2026 and August 20, 2026 respectively.

## The numbers

| Metric | Birdathon | Stoichiometry Pro |
| --- | --- | --- |
| Price | **Free** | $3.99 |
| Rating | **[4.7 (15 ratings)](https://appshunter.io/ios/app/birdathon/id1211977440/reviews)** | — |
| Number of ratings | **15** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 4 months | Every 4 months |
| Monetization | Free | — |
| Size | 192 MB | 2 MB |
| Requires iOS | **16.1** | 17.0 |
| Devices | iPhone, iPad | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Barry Langdon-Lassagne](https://appshunter.io/developer/730758814) | [Roman Volinsky](https://appshunter.io/developer/977951850) |

## What reviewers say

### Birdathon

[App page](https://appshunter.io/ios/app/birdathon/id1211977440)

This app helps birdwatchers create and organize detailed checklists of their observations. It automatically records time and location, allowing for easy editing and customization. Users can visualize their sightings on maps, add field notes, and export data for sharing or further analysis.

**Highlights:** Observation-centric checklists, Automatic time and location recording, Customizable maps with boundary overlays, Field notes for additional observations, Multiple checklist sorting options, Data export to CSV and other formats, Create checklist templates

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Good Tip | $0.99 | one-time |
| Great Tip | $1.99 | one-time |
| Amazing Tip | $2.99 | one-time |
| Incredible Tip | $4.99 | one-time |


### Stoichiometry Pro

[App page](https://appshunter.io/ios/app/stoichiometry-pro/id1546919546)

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

**In-app purchases:** none


## Frequently asked questions

### Is Birdathon free?

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

### Is Stoichiometry Pro free?

Stoichiometry Pro costs $3.99, with no in-app purchases.

### Do Birdathon or Stoichiometry Pro have ads?

Neither Birdathon nor Stoichiometry Pro shows ads.

### Which is updated more often, Birdathon or Stoichiometry Pro?

Birdathon ships an update every 4 months, and Stoichiometry Pro every 4 months. Most recently, Birdathon was updated on September 19, 2026 and Stoichiometry Pro on August 20, 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.*