Comparison

QRCode Scanner · CodeGenerator vs CO2 Calculator

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

Head to head
About

QRCode Scanner · CodeGenerator

Easily scan QR codes from your camera or photos, and generate your own for text, social media links, or WiFi connections. Keep a history of all your scans and access them anytime.

Highlights
  • Scan QR codes from camera
  • Generate QR codes for text
  • Generate social media link QR codes
  • Scan QR codes from images
  • Connect to WiFi via QR code
  • Maintain scan history
Features
Read full description

In the digital age, QR codes have become a bridge connecting information. Whether you want to access product details or add a friend, a simple scan brings it all to you. With our QR code app, you can generate text-based QR codes and scan QR codes, meeting all your QR code scanning needs. Whether you need to parse complex QR code content or perform QR code scanning, we provide a smooth, efficient, all-in-one service. Detailed Features: Text – Add text descriptions below the generated QR code to make information delivery more intuitive. Scan – Point your camera at a QR code to instantly retrieve the information it contains. No extra steps are needed to parse the content. History – Every scan you make is saved on your device, allowing you to easily review past records and access previously obtained information at any time. Image – Import photos from your album to scan QR codes. Simply select an image, and the app will recognize and extract the QR code information. Social – Effortlessly create a QR code that consolidates your social media links. Scan it to visit your Twitter, Instagram, WhatsApp, and other profiles—an ideal tool for making friends. WiFi Connection – Say goodbye to remembering complicated WiFi passwords. Support for scanning to connect to wireless networks directly. Product Advantages: - Efficient and portable, safe and reliable - Easy to use, multi-functional scanning QRCode Scanner – Not just scanning, but a great assistant for your QR code experience. Subscription Notes: • Upon purchase confirmation, payment will be immediately deducted from your iTunes account. • Subscriptions automatically renew by default. To cancel, please manually cancel at least 24 hours before the current period expires; otherwise, the next period's fee will be automatically charged. • The system will automatically deduct the renewal fee for the next period within 24 hours before the expiry date of each period. • Subscription management (including canceling automatic renewal) can be done at any time after purchase in the "Subscriptions" section of your Apple ID account settings. • Please note: Cancellation is not supported during the current billing cycle, and existing subscriptions cannot be terminated early or refunded. Links: Privacy Policy: https://qrcodescannerguide.com/privacy.html Terms of Service: https://qrcodescannerguide.com/terms.html Subscription Terms: https://qrcodescannerguide.com/subscription_terms.html

About

CO2 Calculator

Features
Read full description

Most CO2 charts hand you one confident number. That number is wrong more often than the hobby admits. This calculator does two things differently. It always returns a range instead of a bare value, and it locks the calculation when your water chemistry breaks the method it relies on. WHY A RANGE INSTEAD OF A NUMBER Nobody in this hobby measures dissolved CO2 directly. It is inferred from carbonate hardness, pH and temperature, and every one of those inputs carries error. A pH reading off by 0.1 shifts the result by about 26 percent. A KH kit that resolves only whole degrees can sit half a degree off at 3 dKH, worth another 17 percent. The app carries the resolution of your actual test through the equation and reports "22 to 31 ppm" instead of "26 ppm". The band is the honest answer. A single value claims a precision your test kit never had. WHEN THE APP REFUSES TO ANSWER The KH/pH method assumes carbonate is the only thing buffering your water. Peat, aquasoil, phosphate buffers and many pH-down products break that assumption: they hold pH down without contributing to KH, and the formula reads that as dissolved CO2 that is not in the tank. In documented soil setups the classic table runs high by a factor of 12 to 19. So the app asks what is in your tank first, locks the KH/pH result when the preconditions fail, and sends you to the drop checker or a delta-pH run instead. A locked screen helps you more than a confident 90 ppm on a tank actually sitting near 5 ppm. THE DELTA-pH METHOD, NOW GUIDED Drive the CO2 out of a water sample, then measure it again. The difference between degassed pH and tank pH gives you CO2 without any KH value at all, because carbonate hardness appears on both sides of the ratio and cancels out. This is the method that still holds on aquasoil and peat, and the app now runs the step it depends on: pick an air stone or a glass left standing, start the timer, and it tells you when the sample is ready. It refuses a baseline that reads below the tank, and says so when your two readings sit closer together than your pH method can resolve. THE PREFACTOR CORRECTION The CO2 table copied across every forum uses a fixed prefactor. That prefactor is temperature dependent. Across the usual temperature window of a planted tank, the common table therefore reads 10 to 21 percent low. This app derives the coefficient for the temperature you actually run. DROP CHECKER A blue to green to yellow scale referenced to the usual 4 dKH solution, including the part most guides leave out: a drop checker lags real conditions by one to two hours. It shows where your CO2 was, not where it is. WHAT THIS APP DOES NOT DO - It does not measure anything. Your test kit or probe does the measuring. - It does not replace water tests. - It is not a fish or plant database. - It does not calculate medication doses. WITHOUT PAYING All three methods, the error bands, the locks, the guided degassing, the drop checker scale with its reference recipe, the tools for tank volume, hardness units and dosing, and pH sessions across the photoperiod with the curve and the drift reading. One tank, with the last 30 saved readings. CO2SCAPE PRO, 6.99 EUR, ONE PURCHASE - Unlimited tanks instead of one. Each tank keeps its own hardness, temperature, substrate declarations, target range and readings. - Unlimited history instead of the last 30 readings - Reminders at your chosen interval while a session runs - CSV export of the readings of the tank you are viewing Pro is a single purchase, not a subscription, and it works with Family Sharing. It extends the record keeping, not the chemistry. YOUR TANK DATA STAYS ON DEVICE Your tank data stays on your device. No login or sync. Google loads third-party ads online; Pro removes them. Apple handles purchases and restores. Recommendations for our other apps load online. Their views and taps are counted as daily totals, without personal profiles or user/device identifiers. See our privacy policy.

Screenshots

QRCode Scanner · CodeGenerator4 screens
CO2 Calculator4 screens

Verdict

The call

The clearest difference is update cadence: QRCode Scanner · CodeGenerator at weekly against CO2 Calculator's every 4 weeks. On price, ads, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. QRCode Scanner · CodeGenerator sells 2 in-app purchases, starting at $5.99 per 7 days and CO2 Calculator sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

QRCode Scanner · CodeGenerator ships an update weekly, CO2 Calculator every 4 weeks. The most recent releases landed on October 31, 2026 and October 29, 2026 respectively.

Scorecard1 real difference · 9 level
QRCode Scanner · CodeGenerator versus CO2 Calculator: the parameters behind the verdict, then further details
ParameterQRCode Scanner · CodeGeneratorCO2 Calculator
PriceFreeFree
Rating4.8 (5 ratings) — better—
Positive reviews6.3% of reviews—
Number of ratings5 — better—
Update frequencyWeekly — betterEvery 4 weeks
AdsYesYes
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhoneiPhone, iPad — better
Requires iOS16.6 — better17.0
Further details — not scored
Size64 MB7 MB
Age rating4+4+
DeveloperWellresion LimitedLevin David Schwab

In-app purchases

2 purchases

QRCode Scanner · CodeGenerator

Subscriptions2
  • QRCode Scanner Ad-Free$5.997 Days
  • QRCode Scanner Ad-Free$15.991 Year
1 purchases

CO2 Calculator

One-time1
  • CO2Scape Pro$5.99

Questions

Is QRCode Scanner · CodeGenerator free?
QRCode Scanner · CodeGenerator is free to download, with in-app purchases available.
Is CO2 Calculator free?
CO2 Calculator is free to download, with in-app purchases available.
Do QRCode Scanner · CodeGenerator or CO2 Calculator have ads?
Both QRCode Scanner · CodeGenerator and CO2 Calculator show ads.
Which is updated more often, QRCode Scanner · CodeGenerator or CO2 Calculator?
QRCode Scanner · CodeGenerator ships an update weekly, and CO2 Calculator every 4 weeks. Most recently, QRCode Scanner · CodeGenerator was updated on October 31, 2026 and CO2 Calculator on October 29, 2026.

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