Comparison

CalcTriangle vs USB Disk

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

Head to head
About

CalcTriangle

This app calculates all unknown sides, angles, area, and perimeter of a right triangle. It supports both imperial and metric units, with precise input options for fractions and measurements.

Highlights
  • Calculates sides, angles, area, and perimeter
  • Supports imperial (feet, inches, fractions) and metric units
  • Precise fraction input
  • Save and load triangle data
  • Simple interface for job sites
Features
Read full description

CalcTriangle is an easy-to-use right triangle calculator built for carpenters, builders, and DIYers. Enter any two sides, or one side and one angle, then tap Calc — CalcTriangle solves the rest and shows all sides, angles, area, and perimeter. Features: • Supports feet, inches, and fractions (down to 1/16") — perfect for construction • Metric mode with centimeters, millimeters, and meters • Tap a field on the triangle to select it, then type your measurement • Foot/Inch buttons with a fraction picker wheel for precise imperial entry • Mode button cycles through display units • Save and load triangles for quick reference on the job site • Clean, simple interface designed for big fingers and bright sunlight Completely rewritten in Swift for iOS 18. Fast, modern, and reliable.

About

USB Disk

Manage and view documents on your iPhone or iPad with this intuitive file manager. Access cloud storage, open various file types, and transfer files via iTunes. Advanced features like photo library access and PDF annotation are available via subscription.

Highlights
  • Cloud storage integration (Dropbox, Google Drive, OneDrive, Box)
  • Built-in document viewer for various file types
  • File transfer via iTunes
  • Create and open zip files
  • Swipe navigation and file previews
  • Email documents and download attachments
Features
Read full description

USB Disk lets you store, view and manage documents on your iPhone or iPad. It has an amazing built in document viewer and is very easy to use, with a simple and intuitive interface, yet it contains many powerful features. Drag and drop files in iTunes to transfer them to your iPhone or iPad, then view them anywhere! TUAW - "USB Disk is [...] a nicely designed one." Lifehacker - "The Best. USB Disk for iOS gives you a fast and easy way to transfer documents and images to your device." Apple - "New and Noteworthy" TOP REASONS TO BUY • Access Dropbox, Google Drive, OneDrive and Box. • Open and create zip files. • Store and view files. • Navigate using swipes (like Photos / iBooks app). • Thumbnails let you preview your files. • Copy, paste, cut, delete and create files. MORE FEATURES • View and download email attachments. • Restores last viewing position. • Full screen file viewer. • CBR and CBZ file viewer. • USB file transfers. • Background audio. • Slideshow with adjustable delay. • Fast scrolling, page up/down functionalities. • Email your documents. • Lock code. SUPPORTED FILE TYPES • PDF files. • Compressed files (zip, rar). • MS Office documents. • iWork documents. • Pictures (jpg, png, gif, ...). • eBooks (pdf, ePub, html, txt, ...). • Comics (cbr, cbz, pdf, ...). • Audio files (mp3, m4a, wav, ...). • Video files (m4v, mov, avi, mkv, ...). UPDATES Buy now and get free updates. SUBSCRIPTION All features listed above can be used without an in app purchase. Some advanced features require an active subscription. These include: • Access the device's photos library. • Protect the access to the app or specific files and folders with lock codes. • Access WebDAV and FTP servers. You can also configure SharePoint connections. • Edit simple text files. Also annotate PDF files. • Present files on external screens. Duration and price of each subscription are displayed in our storefront. All subscription costs will be charged to your Apple ID account, starting at the confirmation of purchase. Subscription automatically renews unless it is canceled at least 24 hours before the end of the subscription period. Your account will be charged for renewal within 24 hours prior to the end of the subscription period. It is not possible to cancel a subscription period once you have been charged for it. Any unused portion of a free trial period is forfeited as soon as a subscription is purchased. You can manage subscriptions and disable auto renewal by going to your account settings on the App Store after purchase. Terms of Service: https://imesart.com/legal/terms-of-service.php

Screenshots

CalcTriangle1 screens
USB Disk4 screens

Verdict

The call

The clearest difference is in-app purchases: CalcTriangle at none against USB Disk's 10. CalcTriangle also leads on ads (none vs shown) and chart position (#194 vs unranked). USB Disk's advantage is review sentiment (71% vs 50%) and update cadence (every 3 months vs every 8 months). On price 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

CalcTriangle costs $0.99 and USB Disk $0.99 up front. USB Disk sells 10 in-app purchases, starting at $4.99 per month. CalcTriangle asks for nothing beyond the download.

UpkeepUpdate frequency

CalcTriangle ships an update every 8 months, USB Disk every 3 months. The most recent releases landed on July 25, 2026 and October 1, 2026 respectively.

Scorecard8 real differences · 3 level
CalcTriangle versus USB Disk: the parameters behind the verdict, then further details
ParameterCalcTriangleUSB Disk
Price$0.99$0.99
Rating—4.6 (160 ratings) — better
Positive reviews50.0% of reviews70.8% of reviews — better
Number of ratings—160 — better
Update frequencyEvery 8 monthsEvery 3 months — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
Best chart rank#194 — better—
DevicesiPhone, iPadiPhone, iPad, iPod, Apple Watch — better
Requires iOS17.612.0 — better
Further details — not scored
Size1 MB170 MB
Age rating4+4+
DeveloperPhilip SacchitellaImesart S.a.r.l.

Customer experience

CalcTriangle

Written reviews10 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

USB Disk

All ratings160 ratings
Positive91.3%
Neutral3.1%
Negative5.6%
Written reviews1,056 reviews
Positive70.8%
Neutral13.9%
Negative15.2%

Bugs and requests

CalcTriangle

Not enough reviews yet to summarise bugs or requests.

USB Disk

Reported bugs

3 issues
  • Inability to open certain file types
  • Compatibility issues with newer iOS versions
  • Syncing problems between devices

Requested features

4 requests
  • Support for more file types
  • Improved integration with cloud storage services
  • Ability to edit and annotate files
  • Better organization and folder management

In-app purchases

None

CalcTriangle

No in-app purchases

10 purchases

USB Disk

Subscriptions1
  • USB Disk Pro Monthly7 Days trial$4.991 Month
One-time9
  • Audio Player +$0.99
  • Zip files support$0.99
  • Dropbox access$0.99
Show 6 more
  • Lock code$0.99
  • Text editor$0.99
  • Evernote access$0.99
  • Google Drive access$0.99
  • OneDrive access$0.99
  • WebDAV access$1.99

Questions

Is CalcTriangle free?
CalcTriangle costs $0.99, with no in-app purchases.
Is USB Disk free?
USB Disk costs $0.99, and also offers in-app purchases.
Do CalcTriangle or USB Disk have ads?
USB Disk shows ads; CalcTriangle does not.
Which is updated more often, CalcTriangle or USB Disk?
CalcTriangle ships an update every 8 months, and USB Disk every 3 months. Most recently, CalcTriangle was updated on July 25, 2026 and USB Disk on October 1, 2026.

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