Comparison

Twin vs DevHabit

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

Head to head
About

Twin

This app combines two calculators into one, allowing for side-by-side or stacked calculations. Easily copy and paste results between calculators or to other apps. It displays formulas for clarity and handles basic arithmetic operations.

Highlights
  • Two calculators in one
  • Side-by-side and stacked display
  • One-touch copy/paste between calculators
  • Copy results to iPhone memory
  • Formula display
  • Basic arithmetic operations
Features
Read full description

A simple and easy-to-use calculator app that combines two calculators into one. Calculators are displayed side by side when the screen is horizontal, and vertically when the screen is vertical. In addition to being able to perform separate calculations with each calculator, calculation results can be also copy and paste with one touch, so you can perform other calculations during calculations, making it even more convenient to use than you might imagine. There is also a free version with ads. Please try it first. https://apps.apple.com/jp/app/t-calc-lite/id1630026837?l=jp 【feature】 1. Calculation results can be copy and paste between two calculators with one touch. 2. The result calculated can be input from one calculator to the other with one touch. ・When press the "→" key, the calculation result of the left calculator is entered at the end of the formula on the right calculator. ・When press the "←" key, the calculation result of the right calculator is entered at the end of the formula on the left calculator. 3. add, subtract, multiply and divide is performed. Do multiplication and division first, then add and subtract. 4. Display the formula The entered formula is displayed under the result, so you can easily check the operations. 5. Calculation results can be copied to iPhone’s memory Calculation results can be pasted into other apps as text , so transcription errors will not occur. Example of use When you find a product for 988 yen for 3 pieces and a product for 1245 yen for 4 pieces while shopping, you can easily calculate "Which is cheaper?" And “How cheaper?"with this calculator. 1) Use the left and right calculators to find the unit price of the product (unit price = product price/number). 2) Tap the "- key" and "arrow key" on either the left or right calculator to calculate the unit price difference. Limitations ・Answer can be calculated up to 9 digits, minimum 0.000000001. Note The free version can be downloaded from https://apps.apple.com/jp/app/t-calc-lite/id1630026837?l=en

About

DevHabit

Features
Read full description

Make Change a Habit, Make Persistence Simple DevHabit is a professional habit tracking app that helps you build good habits and break bad ones using science-backed methods for personal growth. Why Choose DevHabit? • Dual Management - Unique good/bad habit classification system for better psychological experience • Home Screen Widgets - 3 widget sizes for instant progress check without opening the app • Smart Analytics - Streak counts, completion rates, trend analysis to witness daily growth • Achievement System - Unlock exclusive badges to stay motivated • Personalized Reminders - Gentle reminders for good habits, warning alerts for bad ones Core Features Habit Management 24 beautiful icons to personalize your habits Separate tracking for good and bad habits Custom reminder times and frequencies Progress Tracking One-tap check-in with intuitive interface Calendar view for historical records Streak counts and cumulative statistics Home Screen Widgets Small: Display 2 important habits Medium: Show 4 habits with progress Large: Complete dashboard view Achievement System 8 carefully designed achievement badges Milestone rewards for consistency Unlock Pro feature previews Pro Features Upgrade to Pro for powerful advanced features: • Unlimited habits (Free version limited to 3) • Advanced analytics and trend charts • iCloud auto-sync - never lose your data • All widget sizes and styles • 100+ professional habit templates • Data export (PDF/Excel formats) • Custom themes and personalization • Priority customer support Special Offers • 7-day free trial of all Pro features • 50% off first month for new users • Annual subscription saves 28% vs monthly Let DevHabit accompany your growth journey. Start today and make change a habit! Privacy Policy: https://gist.github.com/mokong/a2b2a5ba51df445acb8f1c47b5ebb08e/raw Terms of Use: https://gist.github.com/mokong/4cb5c50f435fcf6b689478051fad47c1/raw

Screenshots

Twin4 screens
DevHabit4 screens

Verdict

The call

The clearest difference is price: DevHabit at Free against Twin's $0.99. Twin's advantage is in-app purchases (none vs 3) and update cadence (every 2 weeks vs every 4 months). 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

DevHabit is free to download; Twin costs $0.99 up front. DevHabit sells 3 in-app purchases, starting at $2.99 per month. Twin asks for nothing beyond the download.

UpkeepUpdate frequency

Twin ships an update every 2 weeks, DevHabit every 4 months. The most recent releases landed on September 21, 2026 and September 10, 2026 respectively.

Scorecard4 real differences · 6 level
Twin versus DevHabit: the parameters behind the verdict, then further details
ParameterTwinDevHabit
Price$0.99Free — better
Rating5.0 (8 ratings) — better—
Positive reviews76.0% of reviews—
Number of ratings8 — better—
Update frequencyEvery 2 weeks — betterEvery 4 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaid—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better16.0
Further details — not scored
Size1 MB3 MB
Age rating4+4+
DeveloperHiroyuki Ueda珍珍 张

In-app purchases

None

Twin

No in-app purchases

3 purchases

DevHabit

Subscriptions2
  • Pro Monthly$2.991 Month
  • Pro Yearly (Best Value)$19.991 Year
One-time1
  • Pro Lifetime$39.99

Questions

Is Twin free?
Twin costs $0.99, with no in-app purchases.
Is DevHabit free?
DevHabit is free to download, with in-app purchases available.
Do Twin or DevHabit have ads?
Neither Twin nor DevHabit shows ads.
Which is updated more often, Twin or DevHabit?
Twin ships an update every 2 weeks, and DevHabit every 4 months. Most recently, Twin was updated on September 21, 2026 and DevHabit on September 10, 2026.

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