737 CSFF vs Plen
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
737 CSFF
A visual guide to understanding Cold Soaked Fuel Frost (CSFF) on 737 aircraft wings. It references airline handbooks and Boeing FCOM guidance for educational purposes.
- Visual representation of CSFF scenarios
- Study guide for 737 wing frost
- References North American Airline Flight Handbook
- Includes Boeing FCOM guidance
- Educational tool for pilots
Read full descriptionHide full description
This app is a study guide and a visual representation to aid in the understanding around the many scenarios when Cold Soaked Fuel Frost (CSFF) is encountered on the wing of a 737. This app is not approved for use during flight operations. The CSFF guidance in this app is designed around a North American Airline Flight Handbook and reference to the Boeing FCOM. This app is not a substitute for company flight manuals, an FAA approved deicing program, Boeing FCOM guidance or good judgement.
Plen
Track aircraft in real-time with live location updates. See planes as they fly and monitor weather conditions along their routes. Discover various types of aircraft with this intuitive radar tool.
- Real-time ADS-B tracking
- Live aircraft location updates
- Weather updates for flight paths
- Discover different types of aircraft
- Intuitive radar interface
Read full descriptionHide full description
Meet Plen. Plens are in the sky all around us. Track plens with Plen, find plens, see plens. All with Plen. Find fun plens, fast plens, slow plens. Plen. Key Features: Real-Time ADS-B Tracking: Plen location updated in real time. Weather Updates: Watch plens fly through sky poofs. Download Plen.
Screenshots
Verdict
The clearest difference is price: Plen at Free against 737 CSFF's $2.99. Plen also leads on update cadence (every 6 days vs every 4 months). On ads, in-app purchases, device support and iOS requirement 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
Plen is free to download; 737 CSFF costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
737 CSFF ships an update every 4 months, Plen every 6 days. The most recent releases landed on October 7, 2026 and October 3, 2026 respectively.
| Parameter | 737 CSFF | Plen |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 5.0 (2 ratings) — better | — |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 2 — better | — |
| Update frequency | Every 4 months | Every 6 days — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Paid | Free — better |
| Devices | iPhone, iPad, Apple Watch — better | iPhone, iPad |
| Requires iOS | 17.6 | 17.0 — better |
| Further details — not scored | ||
| Size | 11 MB | 203 MB |
| Age rating | 4+ | 4+ |
| Developer | Dan O'Leary | Automata Solutions Ltd. |
Customer experience
737 CSFF
Plen
In-app purchases
737 CSFF
No in-app purchases
Plen
No in-app purchases
