Comparison

Project Monarch Science vs SoulTuner

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

SoulTuner

Features
Read full description

SoulTuner provides a simple way for you to explore the effects of binaural beats where each ear receives a slightly different frequency. This is said to produce feelings of relaxation or greater focus depending on the settings. Use the knobs to adjust the base (Carrier) frequency to one that feels right for you. Optionally, add harmony voices and reverb for a fuller sound or listen to a complex harmony of drones all by itself. Features —Pure binaural sine waves, one for each ear in headphones —Music toggle to switch to musical notes instead of raw frequencies —Toggle to swap left and right for binaural sources —Up to 25 additional color-coded interval harmony drones over two octaves (but less is often more) —Add automated panning to gently move drones around —Add reverb for fuller spacial sound —Change harmony drone voices —Create ambient noise of various pleasing types: Pink, Brown, Green, Gray, White and add a slow sweep to change it —Add a low slow pulse synchronized to the other audio for extra relaxation —Use a timer to turn everything off after awhile, good for a sleep setting —Can run in the background while you do other things or have your device screen off Uses —Explore relaxation and focus properties of binaural audio —Find frequencies that feel right for you —Use the massive drone stack out to a recording device

Screenshots

Project Monarch Science4 screens
SoulTuner4 screens

Verdict

The call

The clearest difference is price: Project Monarch Science at Free against SoulTuner's $0.99. Project Monarch Science also leads on iOS requirement (15.0 vs 18.6). On update cadence, ads, in-app purchases and device support 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

Project Monarch Science is free to download; SoulTuner costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Project Monarch Science ships an update every 10 days, SoulTuner every 5 days. The most recent releases landed on November 3, 2026 and November 1, 2026 respectively.

Scorecard2 real differences · 8 level
Project Monarch Science versus SoulTuner: the parameters behind the verdict, then further details
ParameterProject Monarch ScienceSoulTuner
PriceFree — better$0.99
Rating4.0 (29 ratings) — better—
Positive reviews60.0% of reviews—
Number of ratings29 — better—
Update frequencyEvery 10 daysEvery 5 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better18.6
Further details — not scored
Size83 MB3 MB
Age rating4+4+
DeveloperCellular Tracking TechnologiesTechné Media

In-app purchases

None

Project Monarch Science

No in-app purchases

None

SoulTuner

No in-app purchases

Questions

Is Project Monarch Science free?
Project Monarch Science is free to download, with no in-app purchases.
Is SoulTuner free?
SoulTuner costs $0.99, with no in-app purchases.
Do Project Monarch Science or SoulTuner have ads?
Neither Project Monarch Science nor SoulTuner shows ads.
Which is updated more often, Project Monarch Science or SoulTuner?
Project Monarch Science ships an update every 10 days, and SoulTuner every 5 days. Most recently, Project Monarch Science was updated on November 3, 2026 and SoulTuner on November 1, 2026.

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