Locklizard Safeguard Viewer vs C172 Performance
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Locklizard Safeguard Viewer
This free application allows users to view protected PDF documents on their iOS devices. It supports secure PDF files that have been protected using specific DRM security software.
- View secure PDF documents
- Supports PDC files
- DRM protected PDF viewing
- iOS compatibility
- Free to use
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Locklizard Safeguard Viewer for iOS is a FREE app that lets you view Locklizard secure PDF documents (PDC files) on the iPad and iPhone. Safeguard Secure PDF Viewer supports PDC files protected with Safeguard PDF Security and Enterprise PDF DRM. An installation video can be found at https://www.locklizard.com/Videos/Viewers/ios-viewer-install.mp4
C172 Performance
This app calculates essential flight performance data for Cessna 172 and 150 aircraft. It covers takeoff, landing, climb, cruise, descent, instrument procedures, and emergencies, with additional tools for holds and glide calculations. Cloud sync ensures your flight plans are accessible across devices.
- Takeoff and landing calculations
- Climb, cruise, and descent performance
- Instrument procedure planning
- Emergency scenario calculations
- Interactive hold calculator
- Emergency glide distance calculator
- Cloud sync for flight plans
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C172 Performance computes all the useful performance numbers for flight planning for Cessna model 172 and 150 aircraft. It includes calculations for takeoff, landing, climb, cruise, descent, instrument procedures as well as emergencies. It also includes an interactive hold calculator, a risk analysis tool, and an emergency glide distance calculator that handles head and tailwinds. C172 Performance is also available on other mobile devices and as a WebApp (an App that runs in a browser) that runs on a variety of platforms (PC, Mac, tablets, phones). The cloud sync feature allows flight planning profiles entered on any device to be synchronized with your other devices when connected to the Internet. C172 Performance is a free, open-source development effort and has Apps and WebApps for other aircraft. See http://pohperformance.com for complete details.
Screenshots
Verdict
The clearest difference is review sentiment: C172 Performance at 90% against Locklizard Safeguard Viewer's 11%. C172 Performance also leads on rating (4.9 vs 1.8) and ratings volume (52 vs 8). Locklizard Safeguard Viewer's advantage is ads (none vs shown) and monetization model (free vs ad-supported). On price, update cadence, 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.
C172 Performance holds the better App Store score, 4.9 against 1.8. That said, the two scores are not equally well evidenced: C172 Performance has 52 ratings behind it against 8, so its average is the more settled of the two. Written reviews point the same way: 11% of Locklizard Safeguard Viewer's written reviews are positive against 90% of C172 Performance's.
Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on September 23, 2026 and September 18, 2026 respectively.
| Parameter | Locklizard Safeguard Viewer | C172 Performance |
|---|---|---|
| Price | Free | Free |
| Rating | 1.8 (8 ratings) | 4.9 (52 ratings) — better |
| Positive reviews | 10.8% of reviews | 90.0% of reviews — better |
| Number of ratings | 8 | 52 — better |
| Update frequency | Every 2 months | Every 2 months |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Free — better | Ad-supported |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 15.6 | 13.0 — better |
| Further details — not scored | ||
| Size | 74 MB | 15 MB |
| Age rating | 4+ | 4+ |
| Developer | LockLizard | POH Performance L.L.C. |
Customer experience
Locklizard Safeguard Viewer
C172 Performance
In-app purchases
Locklizard Safeguard Viewer
No in-app purchases
C172 Performance
No in-app purchases
Questions
Is Locklizard Safeguard Viewer free?
Is C172 Performance free?
Which has better reviews, Locklizard Safeguard Viewer or C172 Performance?
Do Locklizard Safeguard Viewer or C172 Performance have ads?
Which is updated more often, Locklizard Safeguard Viewer or C172 Performance?
Other comparisons
