Sader Method vs Protractor Edge
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Sader Method
This utility app helps calibrate Atomic Force Microscope cantilevers. It provides a user interface to determine the spring constant of a cantilever using its resonant frequency and quality factor.
- Atomic Force Microscope cantilever calibration
- Determine spring constant
- Resonant frequency measurement
- Quality factor measurement
- User interface for calibration
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Calibrate Atomic Force Microscope cantilevers using the Sader Method. Provides a user interface for determining the spring constant of a cantilever from measurements of its resonant frequency and quality factor.
Protractor Edge
Measure angles directly on your device without taking photos or placing the angle on screen. This app offers a unique and efficient way to determine degrees, saving you time with its handy assistant functionality.
- Direct angle measurement on device
- Intuitive line dragging interface
- Measures angles in photos (Premium)
- Measures from camera view (Premium)
- Ad-free experience (Premium)
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A simple protractor. Just put your device on the angle you want to measure. Then drag the two lines to align the both sides of the angle. The degrees will be there. It is different from other protractor apps. This is a new way to measure angles. It requires neither taking photo nor putting the angle above the screen. Now start using this handy assistant to measure angles which will save you a lot of time. ------------------------------------- PREMIUM ACCESS SUBSCRIPTION - Measure the world from camera - Measure angles in photos - No Ads - The subscription is $0.99 yearly with trial - Payment will be charged to iTunes Account at confirmation of purchase - Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period - Account will be charged for renewal within 24-hours prior to the end of the current period, and identify the cost of the renewal - Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Settings after purchase - Any unused portion of a free trial period, if offered, will be forfeited when the user purchases a subscription to that service, where applicable - Terms of use: https://service.notationpad.com/terms_service.html
Screenshots
Verdict
The clearest difference is rating: Sader Method at 5.0 against Protractor Edge's 4.5. Sader Method also leads on in-app purchases (none vs 2) and ads (none vs shown). Protractor Edge's advantage is ratings volume (55 vs 1) and iOS requirement (9.0 vs 15.4). On price, update cadence 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. Protractor Edge sells 2 in-app purchases, starting at $1.99 per year. Sader Method asks for nothing beyond the download.
Sader Method holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Protractor Edge has 55 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 100% of Sader Method's written reviews are positive against 70% of Protractor Edge's.
Sader Method ships an update every 57 months, Protractor Edge every 43 months. The most recent releases landed on September 17, 2026 and October 11, 2026 respectively.
| Parameter | Sader Method | Protractor Edge |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.5 (55 ratings) |
| Positive reviews | 100.0% of reviews — better | 69.6% of reviews |
| Number of ratings | 1 | 55 — better |
| Update frequency | Every 57 months | Every 43 months — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Freemium |
| Devices | iPhone, iPod | iPhone, iPad, iPod — better |
| Requires iOS | 15.4 | 9.0 — better |
| Further details — not scored | ||
| Size | 2 MB | 21 MB |
| Age rating | 4+ | 4+ |
| Developer | John Sader | 嵩 张 |
Customer experience
Sader Method
Protractor Edge
In-app purchases
Sader Method
No in-app purchases
Protractor Edge
- Premium Access7 Days trial$1.991 Year
- Remove Ads$0.99
Questions
Is Sader Method free?
Is Protractor Edge free?
Which has better reviews, Sader Method or Protractor Edge?
Do Sader Method or Protractor Edge have ads?
Which is updated more often, Sader Method or Protractor Edge?
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