Comparison

RedoCalc vs Stopwatch Library

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

Head to head
About

RedoCalc

Features
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This is a calculator for people who only use it for simple calculations, such as adding up receipts or calculating the cost of a meal split between several people, but who are always worried about whether the input was correct. As it is a simple calculator, the only operations it can perform are - Four arithmetic operations (addition, subtraction, multiplication, division) - Percentage calculations (including calculations such as consumption tax using percentages) . The results are displayed as numbers with a digit symbol. There is no complicated exponential display. The calculation proceeds in the order of the keys you enter. There is no priority for multiplication or division. The formulas you enter are displayed in order in the upper area as a history. If you tap the white part, it will turn yellow and you will be able to modify that part. (You can modify not only numbers, but also arithmetic symbols such as + and ×.) If you tap “=”, the expressions from the first line to the last line will be recalculated. The result will be automatically copied, so you can switch to other apps and paste the value there.

About

Stopwatch Library

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複数のストップウォッチを表示させることができます。 アナログかデジタルかは選んでください。

Screenshots

RedoCalc3 screens
Stopwatch Library4 screens

Verdict

The call

The clearest difference is in-app purchases: RedoCalc at none against Stopwatch Library's 1. Stopwatch Library's advantage is ads (none vs shown). On price, update cadence, 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Stopwatch Library sells 1 one-off in-app purchase. RedoCalc asks for nothing beyond the download.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 days. The most recent releases landed on September 25, 2026 and September 28, 2026 respectively.

Scorecard2 real differences · 4 level
RedoCalc versus Stopwatch Library: the parameters behind the verdict, then further details
ParameterRedoCalcStopwatch Library
PriceFreeFree
Update frequencyEvery 3 daysEvery 3 days
AdsYesNo — better
In-app purchasesNo — betterYes
DevicesiPhoneiPhone, iPad — better
Requires iOS18.017.0 — better
Further details — not scored
Size3 MB5 MB
Age rating4+4+
DeveloperToshiyuki KuwabaraNaoyuki Hasegawa

In-app purchases

None

RedoCalc

No in-app purchases

1 purchases

Stopwatch Library

One-time1
  • 広告を削除$2.99

Questions

Is RedoCalc free?
RedoCalc is free to download, with no in-app purchases.
Is Stopwatch Library free?
Stopwatch Library is free to download, with in-app purchases available.
Do RedoCalc or Stopwatch Library have ads?
RedoCalc shows ads; Stopwatch Library does not.
Which is updated more often, RedoCalc or Stopwatch Library?
RedoCalc ships an update every 3 days, and Stopwatch Library every 3 days. Most recently, RedoCalc was updated on September 25, 2026 and Stopwatch Library on September 28, 2026.

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