Comparison

Birdathon vs GRE Math Calculator 2025

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

Head to head
About

Birdathon

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
Read full description

Birdathon is an observation-centric tool for creating birding checklists. It helps you organize your checklists and share them with others. Use Birdathon in the field to quickly record whether and where a bird is seen or heard and the number observed. The time and location of each observation is automatically recorded. You can adjust the location, time entries and the count of birds observed at any time to ensure your records are accurate. You can add breeding codes to your observations. Checklist maps display the locations of your observations. You can overlay county boundaries for every US state. You can add a range circle such as a 5MR (5-mile Radius) to your maps. You can import and overlay custom kml/kmz files onto your maps. An Overview feature lets you see your combined observations for any time period, and displays a map showing any boundaries you have selected, so you can utilize the map feature even when you are not actively checklisting. You can export Overview data into a csv text file or create a new checklist template from the Overview. Your checklists can be viewed in taxonomic order, alphabetically, by rarity or as a timeline of species. You can enrich your checklist with field notes and add observations such as mammals, butterflies, wildflowers, etc., to make it a more complete record of your experience. You can organize your checklists into categories such as Day List, Year List, County List, Life List, etc., and assign color themes to your lists. Bird species may be added and deleted from your lists at any time. You can create new checklist templates from your previous lists or import templates created by others. You can change which template is being used. You can import text files into Birdathon, making them into templates or new checklists. Different export options for your checklists allow you to import into eBird or another copy of Birdathon. The bird species source data and other resources used in this app come from the following sources: AviList, a unified global checklist of birds, is the core data set used for Birdathon. https://www.avilist.org. Some data has been integrated from the following sources: The eBird/Clements checklist of birds of the world (https://www.birds.cornell.edu/clementschecklist/download/), the American Ornithological Society's (AOS) Checklist of North and Middle American Birds (https://checklist.americanornithology.org), and the American Birding Association's (ABA) checklist of North American Birds (https://www.aba.org/listing-taxonomy/) Alpha codes come from The Institute for Bird Populations’ Standardized 4- and 6-letter Bird Species Codes. https://www.birdpop.org/pages/birdSpeciesCodes.php. County boundary data is from the United States Geological Survey (USGS) TIGER/Line 2019 Shapefiles found on the United States Census Bureau's website at https://www.census.gov/geographies/mapping-files/time-series/geo/tiger-line-file.2019.html. Boundaries should be used as general guidelines and not be considered precise. Note especially where county boundaries follow creeks, rivers, ridge lines and other natural features, and so are of much finer resolution than can be shown on Birdathon’s maps. California breeding bird atlas blocks come from the California Bird Atlas, https://www.californiabirdatlas.org. California Bird Atlas logo and breeding code descriptions used with permission.

About

GRE Math Calculator 2025

This app simulates the official GRE math calculator, offering features like parentheses, memory functions, and a realistic timer. It aims to help users practice calculations with the same behavior as the ETS PowerPrep tool, reducing errors and improving speed.

Highlights
  • Official ETS PowerPrep behavior simulation
  • Parentheses for faster calculations
  • Memory functions (M+, MR, MC)
  • Thousands separator
  • Realistic timer
  • Transfer Display button
Features
Read full description

IMPORTANT: This is not an ETS official app! Why do I need a GRE calculator? > Using "(" and ")" can speed up your calculation and reduce mistakes, but this functionality is not commonly provided by built-in calculators. Why is this GRE calculator different from others? > It followed the exact same behavior as the calculator in the ETS official PowerPrep math section. Feature * Limited precision * Thousands separator * "ERROR" sign * Depth 1 "(" and ")" * "M+", "MR", "MC" and Memory "M" sign * "Transfer Display" button * Realistic timer Please feel free to contact us if you have any ideas to make this app better!

Screenshots

Birdathon4 screens
GRE Math Calculator 20254 screens

Verdict

The call

The clearest difference is in-app purchases: Birdathon at none against GRE Math Calculator 2025's 2. Birdathon also leads on ads (none vs shown) and rating (4.7 vs 4.4). GRE Math Calculator 2025's advantage is update cadence (every 8 days vs every 4 months) and iOS requirement (12.0 vs 16.1). On price 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

Both are free to download. GRE Math Calculator 2025 sells 2 in-app purchases, starting at $4.99 per month. Birdathon asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Birdathon holds the better App Store score, 4.7 against 4.4. Both are backed by a comparable volume of ratings — 15 and 5 respectively.

UpkeepUpdate frequency

Birdathon ships an update every 4 months, GRE Math Calculator 2025 every 8 days. The most recent releases landed on November 2, 2026 and November 3, 2026 respectively.

Scorecard7 real differences · 3 level
Birdathon versus GRE Math Calculator 2025: the parameters behind the verdict, then further details
ParameterBirdathonGRE Math Calculator 2025
PriceFreeFree
Rating4.7 (15 ratings) — better4.4 (5 ratings)
Positive reviews100.0% of reviews—
Number of ratings15 — better5
Update frequencyEvery 4 monthsEvery 8 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationFree — betterFree with in-app purchases
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS16.112.0 — better
Further details — not scored
Size192 MB31 MB
Age rating4+4+
DeveloperBarry Langdon-LassagnePoChu. Hsu

Customer experience

Birdathon

All ratings15 ratings
Positive93.3%
Neutral0.0%
Negative6.7%
Written reviews11 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

GRE Math Calculator 2025

All ratings5 ratings
Positive80.0%
Neutral0.0%
Negative20.0%

In-app purchases

None

Birdathon

No in-app purchases

2 purchases

GRE Math Calculator 2025

Subscriptions1
  • AI Tutor$4.991 Month
One-time1
  • Remove Ads$9.99

Questions

Is Birdathon free?
Birdathon is free to download, with no in-app purchases.
Is GRE Math Calculator 2025 free?
GRE Math Calculator 2025 is free to download, with in-app purchases available.
Which has better reviews, Birdathon or GRE Math Calculator 2025?
Birdathon is rated higher. Birdathon averages 4.7 out of 5 from 15 ratings, while GRE Math Calculator 2025 averages 4.4 from 5 ratings.
Do Birdathon or GRE Math Calculator 2025 have ads?
GRE Math Calculator 2025 shows ads; Birdathon does not.
Which is updated more often, Birdathon or GRE Math Calculator 2025?
Birdathon ships an update every 4 months, and GRE Math Calculator 2025 every 8 days. Most recently, Birdathon was updated on November 2, 2026 and GRE Math Calculator 2025 on November 3, 2026.

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