Comparison

A.I.M. vs GSA Per Diem

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

Head to head
About

A.I.M.

This application is designed for engineers and authorized personnel within Audubon. It provides access to specific tools and information relevant to their professional roles.

Highlights
  • Engineering tools
  • Authorized user access
  • Professional role information
  • Audubon specific features
Features
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Audubon app for engineers and authorized users

About

GSA Per Diem

This app helps federal travelers plan trips and calculate per diem expenses. It provides up-to-date lodging and meal rates for various US destinations and allows for the generation of detailed trip expense reports. Export your findings as PDFs or CSV files for easy sharing and record-keeping.

Highlights
  • Per diem rate lookup by location and fiscal year
  • Calculate lodging, meals, and incidental expenses
  • Generate trip expense reports
  • Export reports to PDF and CSV
  • Handles cross-fiscal year travel
  • Excludes lodging on final travel day
Features
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Plan federal travel and calculate per diem expenses with US Per Diem. Look up lodging and meals and incidental expenses (M&IE) rates for destinations across the United States, including Alaska, Hawaii, Puerto Rico, Guam, American Samoa, and the U.S. Virgin Islands. Rate information is sourced from data published by the U.S. General Services Administration (GSA) and the Defense Travel Management Office (DTMO). PER DIEM RATE LOOKUP • Search by state or territory, fiscal year, and location. • View monthly lodging and M&IE rates. • Review breakfast, lunch, dinner, and incidental expense allocations. • See the 75% M&IE allowance for first and last travel days. TRIP EXPENSE REPORTS • Select a destination and travel dates to calculate estimated reimbursement. • View a daily breakdown of lodging, meals, and incidental expenses. • Use the applicable rate when a trip crosses fiscal years. • Automatically exclude lodging on the final travel day. PDF AND CSV EXPORTS • Export rate lookups and complete trip reports. • Open reports in compatible PDF and spreadsheet apps. • Save or share files using the standard iOS sharing options. US Per Diem is useful for federal travelers, travel coordinators, and anyone who needs a convenient per diem calculator or travel expense report. US Per Diem is an independent reference and planning tool. It is not affiliated with or endorsed by GSA, DTMO, the Department of Defense, or the U.S. government. Always confirm applicable rates and reimbursement rules with your organization before travel or submission.

Screenshots

A.I.M.4 screens
GSA Per Diem4 screens

Verdict

The call

The clearest difference is rating: GSA Per Diem at 5.0 against A.I.M.'s 3.7. A.I.M.'s advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, ratings volume, 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

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

ReceptionRating · Positive reviews · Number of ratings

GSA Per Diem holds the better App Store score, 5.0 against 3.7. Both are backed by a comparable volume of ratings — 3 and 2 respectively.

UpkeepUpdate frequency

A.I.M. ships an update fortnightly, GSA Per Diem monthly. The most recent releases landed on October 12, 2026 and October 25, 2026 respectively.

Scorecard5 real differences · 4 level
A.I.M. versus GSA Per Diem: the parameters behind the verdict, then further details
ParameterA.I.M.GSA Per Diem
PriceFreeFree
Rating3.7 (3 ratings)5.0 (2 ratings) — better
Number of ratings3 — better2
Update frequencyFortnightly — betterMonthly
AdsNo — betterYes
In-app purchasesNoNo
MonetizationFree — betterAd-supported
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.0 — better14.0
Further details — not scored
Size34 MB48 MB
Age rating4+17+
DeveloperAudubon Engineering Operations, LLCKiarash Torkian

In-app purchases

None

A.I.M.

No in-app purchases

None

GSA Per Diem

No in-app purchases

Questions

Is A.I.M. free?
A.I.M. is free to download, with no in-app purchases.
Is GSA Per Diem free?
GSA Per Diem is free to download, with no in-app purchases.
Which has better reviews, A.I.M. or GSA Per Diem?
GSA Per Diem is rated higher. A.I.M. averages 3.7 out of 5 from 3 ratings, while GSA Per Diem averages 5.0 from 2 ratings.
Do A.I.M. or GSA Per Diem have ads?
GSA Per Diem shows ads; A.I.M. does not.
Which is updated more often, A.I.M. or GSA Per Diem?
A.I.M. ships an update fortnightly, and GSA Per Diem monthly. Most recently, A.I.M. was updated on October 12, 2026 and GSA Per Diem on October 25, 2026.

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