Comparison

Calca vs SPYDERWEB

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

Head to head
About

Calca

This app is an advanced symbolic calculator and text editor. It solves equations, simplifies expressions, and allows you to explain your work alongside calculations. Calculations update instantly as you type, and all data is stored as plain text for easy sharing and device syncing.

Highlights
  • Symbolic calculation
  • Equation solving
  • Expression simplification
  • Markdown text editor
  • Real-time updates
  • Unit and currency conversion
  • Matrix operations
Features
Read full description

Calca is a powerful symbolic calculator that gives you instant answers as you type. It solves equations and simplifies complex expressions - it's a computer algebra system in your pocket! It's also a rich Markdown text editor so that you can explain your ideas alongside your calculations. Calca is perfect for professionals and students - anyone who works with numbers and equations. Variables and functions can be created with only a few keystrokes and can be manipulated with a rich library of operators and functions. Calca updates as you type - just like a spreadsheet. You can declare variables, edit their values and watch everything update before your eyes. Since everything is calculated on the device - no network needed - you get answers instantaneously. All calculations are stored as plain text so you can easily share them with other editors and move them from device to device. Calca has been designed to work with iCloud documents so all your devices can access your calculations - you'll always have the latest files ready for viewing and editing. Calca comes with a suite of examples to help you get started covering topics from home mortgages to kinetics. All these examples are fully explained within Calca itself. Are you still using a desktop calculator? Are you using the calculator with the giant buttons that came with your OS? Computers are much more capable than doing simple one-line arithmetic - put your machine to work with Calca! Calculation Features: • Variables `x = 42` • Functions `f(c) = 9/5*c + 32` and even recursive functions • Units `42 mph in kmph` and currency `¥599 in $` • Solves equations (`x + 2x + 4x = 42`, what is x?) • Matrices with inverses so you can solve linear equations • Sum, prod, map, and reduce operations on lists, matrices, and ranges • Trigonometry and complex numbers • Derivatives of functions • Logic operations and if statements • Binary math (& and |) and support for binary and hex number (`0xA9` and `0b1010`) • Keeps track of units (m, s, m/s, m/s^2, etc.) so you can verify your equations as you compute Please visit http://calca.io to see lots of examples. Thank you for looking!

About

SPYDERWEB

Features
Read full description

The MEYER app offers a seamless way to remotely access MEYER SPYDERWEB connected devices using a smartphone or tablet. Login to your SPYDERWEB account to securely view your fleet of MEYER devices. Use device dashboards to see the status and key operating metrics of your device in real-time. Access logged data.

Screenshots

Calca4 screens
SPYDERWEB4 screens

Verdict

The call

The clearest difference is price: SPYDERWEB at Free against Calca's $9.99. SPYDERWEB also leads on in-app purchases (none vs 2) and update cadence (weekly vs every 5 months). Calca's advantage is iOS requirement (15.0 vs 17.0). On ads 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

CostPrice · In-app purchases · Ads · Monetization

SPYDERWEB is free to download; Calca costs $9.99 up front. Calca sells 2 one-off in-app purchases. SPYDERWEB asks for nothing beyond the download.

UpkeepUpdate frequency

Calca ships an update every 5 months, SPYDERWEB weekly. The most recent releases landed on September 18, 2026 and September 13, 2026 respectively.

Scorecard4 real differences · 6 level
Calca versus SPYDERWEB: the parameters behind the verdict, then further details
ParameterCalcaSPYDERWEB
Price$9.99Free — better
Rating4.5 (153 ratings) — better—
Positive reviews76.5% of reviews—
Number of ratings153 — better—
Update frequencyEvery 5 monthsWeekly — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.0 — better17.0
Further details — not scored
Size78 MB60 MB
Age rating4+4+
DeveloperKrueger Systems, Inc.GJR Meyer Service Inc.

Bugs and requests

Calca

Reported bugs

12 issues
  • Magic Keyboard causes number input to overwrite instead of append
  • Text selection before numbers triggers increment/decrement instead of selecting
  • Cursor jumps forward and backward with external keyboards
  • iPad Pro keyboard truncation in portrait mode
  • Arrow key (=>) doesn't work in landscape mode
Show 7 more
  • App crashes on startup on some devices
  • File saving is temperamental and causes data loss
  • Folders don't persist unless calculations created within them
  • Large number calculations lose precision (10^100 + 1 - 10^100 returns 0 instead of 1)
  • Keyboard focus issues on iPad with Magic Keyboard
  • iOS 13+ button adaptation issues
  • Spinning beach ball on very large calculations

Requested features

15 requests
  • Files app and document browser integration
  • Dropbox and Google Drive support
  • Date calculation functionality
  • Looping and iteration support
  • User-defined function storage in separate files
Show 10 more
  • Temperature unit support (Celsius, Fahrenheit)
  • Logarithmic and non-proportional unit definitions
  • Multiple parametric plots simultaneously
  • Landscape mode optimization
  • Tabular data and multi-row markdown table support
  • Dark mode (now implemented)
  • Subscription model option for ongoing development
  • Decimal place formatting control
  • Charting and financial functions
  • Better document management interface

SPYDERWEB

Not enough reviews yet to summarise bugs or requests.

In-app purchases

2 purchases

Calca

One-time2
  • 6-Month Optional Patronage$4.99
  • 12-Month Optional Patronage$7.99
None

SPYDERWEB

No in-app purchases

Questions

Is Calca free?
Calca costs $9.99, and also offers in-app purchases.
Is SPYDERWEB free?
SPYDERWEB is free to download, with no in-app purchases.
Do Calca or SPYDERWEB have ads?
Neither Calca nor SPYDERWEB shows ads.
Which is updated more often, Calca or SPYDERWEB?
Calca ships an update every 5 months, and SPYDERWEB weekly. Most recently, Calca was updated on September 18, 2026 and SPYDERWEB on September 13, 2026.

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