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.
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.
- Engineering tools
- Authorized user access
- Professional role information
- Audubon specific features
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Audubon app for engineers and authorized users
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.
- 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
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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
Verdict
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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
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.
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.
| Parameter | A.I.M. | GSA Per Diem |
|---|---|---|
| Price | Free | Free |
| Rating | 3.7 (3 ratings) | 5.0 (2 ratings) — better |
| Number of ratings | 3 — better | 2 |
| Update frequency | Fortnightly — better | Monthly |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 12.0 — better | 14.0 |
| Further details — not scored | ||
| Size | 34 MB | 48 MB |
| Age rating | 4+ | 17+ |
| Developer | Audubon Engineering Operations, LLC | Kiarash Torkian |
In-app purchases
A.I.M.
No in-app purchases
GSA Per Diem
No in-app purchases









