DuelTool vs CalcBoard
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DuelTool
This utility helps manage life points and battle calculations for YU-GI-OH! duels. It features intuitive controls for increasing or decreasing life points, calculating battle damage, and supports special card effects. Additional functions include dice rolling, coin flips, and undo/reset options for a smoother gameplay experience.
- Life Point calculation
- Battle Phase damage calculation
- Special card effect support
- Dice and coin support
- Undo and reset functions
- Customizable buttons
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[Features of the application] This is a tool to use when the duel in YU-GI-OH!. Can calculate the Life Points of the player. [How to use] When the bar is red, Life Points will reduce. Conversely, When the bar is blue, Life Points will increase. If you tap the Life Points part, you can change the player to reduce the Life Points. [Other Functions] Calculation of the Battle Phase damage.(VS button) Supports Shrinka and Solemn Judgment.(1/2 button) Supports dice and coin. Supports undo and reset. Can customize the upper 3 buttons from setting screen. Come on, let's start duel! #This app and developers, have no relationship with KAZUKI TAKAHASHI/SHUEISHA /KONAMI.
CalcBoard
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CalcBoard is a calculator with no ads, no subscriptions, and no tracking. Compare prices side by side, run multiple calculations at once, and get precise results — without a single pop-up interrupting your math. NO ADS. NO SUBSCRIPTIONS. EVER. CalcBoard will never interrupt your calculations with pop-ups, banners, or full-screen ads. Premium features are available through a single one-time purchase — no monthly charges, no recurring fees. COMPARE PRICES SIDE BY SIDE Shopping for the best deal? Open two calculators on the same screen and compare unit prices, discounts, or totals without switching back and forth. CalcBoard is the fastest way to figure out which option actually saves you money. MULTIPLE CALCULATORS, ONE SCREEN Run up to eight independent calculator panels simultaneously. Compare prices, check homework, run different scenarios, or calculate tips for a split bill — all without losing your place. SEE YOUR WORK Every expression stays visible as you type — no more guessing what you entered. Every calculation is saved automatically; bookmark and label the important ones, and with Premium search your full history and export it to CSV. FOUR POWERFUL MODES • Basic — Clean, fast arithmetic for everyday math • Scientific — Trig, logs, exponents, and advanced functions • Programmer — Hex, binary, octal, and decimal shown at the same time, with bitwise operations • Unit Converter — 79 units across 10 categories: length, mass, temperature, area, speed, time, data, volume, energy, pressure SHARED VALUE TRAY Push any result to the shared value tray and pull it into another panel. Chain calculations across panels without retyping numbers. NAMED VARIABLES Type tax=0.0825 once, then use price*tax in any panel. Your variables persist between sessions and work in every calculator mode. INSTANT ACCESS FROM CONTROL CENTER (iOS) Add CalcBoard to your iPhone's Control Center and launch it in a single tap from any screen — no hunting through your home screen. Open Settings → Control Center to add the CalcBoard control. PRECISE RESULTS CalcBoard uses arbitrary-precision decimal arithmetic. No floating-point rounding errors. 0.1 + 0.2 = 0.3, exactly. YOUR DATA STAYS ON YOUR DEVICE No ad SDKs, no analytics trackers, no unnecessary permissions. Your calculations are stored locally and never leave your device. DESIGNED FOR EVERYONE • VoiceOver and TalkBack labels on every key • Light and dark themes with 8 color options and 6 button styles • Large touch targets and haptic feedback on every button • Full iPad support with Split View and hardware keyboards FREE TO START, PAY ONCE TO UNLOCK Two calculator panels and basic mode are free, forever. One purchase unlocks everything — scientific mode, programmer mode, full unit converter, extra panels, shared value tray, full history with search and export, themes, and more. No subscriptions. No recurring charges.
Screenshots
Verdict
The clearest difference is in-app purchases: DuelTool at none against CalcBoard's 1. DuelTool also leads on iOS requirement (7.0 vs 16.0). On price, update cadence, 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
Both are free to download. CalcBoard sells 1 one-off in-app purchase. DuelTool asks for nothing beyond the download.
DuelTool ships an update every 2 months, CalcBoard every 3 months. The most recent releases landed on October 13, 2026 and October 16, 2026 respectively.
| Parameter | DuelTool | CalcBoard |
|---|---|---|
| Price | Free | Free |
| Rating | 1.0 (1 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 2 months — better | Every 3 months |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPod | iPhone, iPad |
| Requires iOS | 7.0 — better | 16.0 |
| Further details — not scored | ||
| Size | 1 MB | 50 MB |
| Age rating | 4+ | 4+ |
| Developer | People Software Corporation | Colby Clark |
In-app purchases
DuelTool
No in-app purchases
CalcBoard
- CalcBoard Premium$2.99









