Comparison

Project Monarch Science vs PerchLens

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Project Monarch Science

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
Read full description

Project Monarch is an effort to leverage recent advances in tracking technology, that have enabled the development of the world’s smallest tracking devices, to track Monarch migration. The tracking devices on the monarch butterflies transmit at the same frequency as Bluetooth which means that everyone with a smartphone is carrying around a receiver in their pocket! This revolutionary approach can potentially create the largest wildlife tracking receiver network in the world, but only if members of the public download and use the free Project Monarch app. These data will allow scientists to track the movements of monarch butterflies in detail never previously imagined. We will see how monarchs utilize key stopping points along migratory routes and learn more about the speed and direction of migration, helping identify the most important sites for habitat conservation and restoration. Ultimately, this technology can help guide conservation planning and lead to increases in monarch populations.

About

PerchLens

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
Read full description

PerchLens leads the way in bird watching innovation. By merging cutting-edge camera tech with classic bird feeders, it captures visiting birds, granting enthusiasts an exclusive peek into our feathered friends' world! It's a complete game-changer in our nature engagement!

Screenshots

Project Monarch Science4 screens
PerchLens4 screens

Verdict

The call

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.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

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

ReceptionRating · Positive reviews · Number of ratings

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.

UpkeepUpdate frequency

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

Scorecard4 real differences · 6 level
Project Monarch Science versus PerchLens: the parameters behind the verdict, then further details
ParameterProject Monarch SciencePerchLens
PriceFreeFree
Rating4.0 (27 ratings) — better1.9 (335 ratings)
Positive reviews60.0% of reviews — better12.0% of reviews
Number of ratings27335 — better
Update frequencyEvery 10 days — betterEvery 3 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.012.0 — better
Further details — not scored
Size83 MB201 MB
Age rating4+4+
DeveloperCellular Tracking TechnologiesPOCKET INC

Customer experience

Project Monarch Science

All ratings27 ratings
Positive74.1%
Neutral0.0%
Negative25.9%
Written reviews15 reviews
Positive60.0%
Neutral0.0%
Negative40.0%

PerchLens

All ratings304 ratings
Positive17.1%
Neutral7.6%
Negative75.3%
Written reviews234 reviews
Positive12.0%
Neutral7.3%
Negative80.8%

Bugs and requests

Project Monarch Science

Not enough reviews yet to summarise bugs or requests.

PerchLens

Reported bugs

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

Requested features

5 requests
  • 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

In-app purchases

None

Project Monarch Science

No in-app purchases

None

PerchLens

No in-app purchases

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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