# Project Monarch Science vs PerchLens

The clearest difference is review sentiment: Project Monarch Science at 60% against PerchLens's 12%. Project Monarch Science also leads on rating (4.0 vs 1.9). PerchLens's advantage is ratings volume (335 vs 27) and iOS requirement (12.0 vs 15.0). On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Project Monarch Science holds the better App Store score, 4.0 against 1.9. That said, the two scores are not equally well evidenced: PerchLens has 335 ratings behind it against 27, so its average is the more settled of the two. Written reviews point the same way: 60% of Project Monarch Science's written reviews are positive against 12% of PerchLens's.

Project Monarch Science ships an update every 10 days, PerchLens every 3 weeks. Both last shipped on October 25, 2026.

## The numbers

| Metric | Project Monarch Science | PerchLens |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.0 (27 ratings)](https://appshunter.io/ios/app/project-monarch-science/id6460006970/reviews)** | [1.9 (335 ratings)](https://appshunter.io/ios/app/perchlens/id6473670884/reviews) |
| Number of ratings | 27 | **335** |
| Positive reviews | **60.0% of reviews** | 12.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 3 weeks |
| Monetization | Free | Free |
| Size | 83 MB | 201 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Cellular Tracking Technologies](https://appshunter.io/developer/1588087267) | [POCKET INC](https://appshunter.io/developer/1717359545) |

## What reviewers say

### Project Monarch Science

[App page](https://appshunter.io/ios/app/project-monarch-science/id6460006970)

This app transforms your smartphone into a receiver for tiny tracking devices attached to monarch butterflies. By crowdsourcing data, it helps scientists monitor butterfly migration patterns in unprecedented detail, aiding conservation efforts.

**Highlights:** Crowdsourced tracking network, Monarch butterfly migration monitoring, Detailed movement data, Habitat conservation insights, Utilizes Bluetooth frequency, Citizen science participation

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

**In-app purchases:** none


### PerchLens

[App page](https://appshunter.io/ios/app/perchlens/id6473670884)

This app enhances bird watching by integrating camera technology with bird feeders to capture images of visiting birds. It offers enthusiasts an innovative way to observe and engage with local wildlife.

**Highlights:** Camera-enabled bird feeder, Captures images of visiting birds, Innovative nature engagement, High-tech bird watching, Feathered friends observation

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

**In-app purchases:** none

**What reviewers like**

- 🚀 Easy to use
- 👍 Works well
- 🚀 Feeder works perfectly
- 👍 Accurate AI recognizer

**What reviewers complain about**

- 🐛 Motion detection too sensitive
- 🐛 Difficult to set up
- 🐛 Unreliable connection
- 🐛 Inaccurate AI bird identification
- 🐛 Camera quality issues

**Reported bugs**

- Inconsistent video recording and storage
- Inability to connect to Wi-Fi
- Login and account issues
- Compatibility problems with newer OS versions

**Requested features**

- Option to turn off AI bird identification
- Improved squirrel deterrent features
- Ability to share videos and photos
- Compatibility with smart home platforms
- Better battery life management


## Frequently asked questions

### Is Project Monarch Science free?

Project Monarch Science is free to download, with no in-app purchases.

### Is PerchLens free?

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

### Which has better reviews, Project Monarch Science or PerchLens?

Project Monarch Science is rated higher. Project Monarch Science averages 4.0 out of 5 from 27 ratings, while PerchLens averages 1.9 from 335 ratings.

### Do Project Monarch Science or PerchLens have ads?

Neither Project Monarch Science nor PerchLens shows ads.

### Which is updated more often, Project Monarch Science or PerchLens?

Project Monarch Science ships an update every 10 days, and PerchLens every 3 weeks. Most recently, Project Monarch Science was updated on October 25, 2026 and PerchLens on October 25, 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.*