Comparison

Conversion vs Battery Testing Master

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

Head to head
About

Conversion

This utility app provides instant conversions between a wide range of units, including metric, imperial, and currency. It features live exchange rates and supports 33 languages, all within a clean, clutter-free interface.

Highlights
  • Extensive unit categories (12 categories, 96 units)
  • Live, offline-capable currency exchange rates
  • Supports 33 languages and regional number formats
  • Modern, clutter-free interface with fluid animations
  • Full VoiceOver and accessibility support
  • No ads, analytics, or tracking
Features
Read full description

Type a number. Read the answer. That is the entire app. Conversion has been on the App Store since 2012. Version 4 is a complete rebuild — modern, quick, and still refreshingly free of clutter. BOTH UNITS, ALWAYS IN VIEW The two units face each other in the middle of the screen, right where you left them last time. Flick either one to change it, or tap an amount to turn the conversion around. Nothing to drill into. TWELVE CATEGORIES, 96 UNITS Length · Area · Volume · Weight · Temperature · Speed · Pressure · Power · Energy · Time · Computing — and Currency, with more than 160 world currencies. LIVE EXCHANGE RATES Rates refresh on their own and are stored on your device, so conversions still work on a plane or underground. When a rate is out of date the app says so, rather than quietly handing you an old number. YOUR LANGUAGE, YOUR NUMBERS 33 languages. Unit names, decimal separators and numbering systems all follow your region — so a comma lands where a comma belongs, and Arabic and Devanagari numerals are drawn properly. BUILT FOR iOS 26 Liquid Glass, a color for every category, fluid animation, haptics, and Dark Mode throughout. ACCESSIBLE FROM THE START Every control is labeled for VoiceOver. Text scales to the largest accessibility sizes. Reduce Motion is respected. A hardware keyboard drives the whole app. NOTHING COLLECTED No account, no ads, no analytics, no tracking. The app makes one kind of network request — for published exchange rates — and it carries nothing about you. Pay once. No subscription.

About

Battery Testing Master

This application benchmarks the battery performance of mobile devices. It provides a comprehensive test for battery health, suitable for both new and used batteries on iOS devices.

Highlights
  • Battery benchmarking
  • Battery health testing
  • Mobile device optimization
  • iOS battery analysis
Features
Read full description

Battery test master is a battery benchmarking application designed specifically for mobile devices. This is also the perfect test for your iOS battery, regardless of whether the battery is new or used, download it now and try it out.

Screenshots

Conversion4 screens
Battery Testing Master4 screens

Verdict

The call

The clearest difference is review sentiment: Conversion at 61% against Battery Testing Master's 0%. Conversion also leads on in-app purchases (none vs 1) and ads (none vs shown). Battery Testing Master's advantage is price (Free vs $0.99) and rating (4.5 vs 3.0). On 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

Battery Testing Master is free to download; Conversion costs $0.99 up front. Battery Testing Master sells 1 one-off in-app purchase. Conversion asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Battery Testing Master holds the better App Store score, 4.5 against 3.0. That said, the two scores are not equally well evidenced: Battery Testing Master has 28 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 61% of Conversion's written reviews are positive against 0% of Battery Testing Master's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Conversion ships an update every 2 months, Battery Testing Master every 5 days. The most recent releases landed on November 10, 2026 and November 4, 2026 respectively.

Scorecard9 real differences · 1 level
Conversion versus Battery Testing Master: the parameters behind the verdict, then further details
ParameterConversionBattery Testing Master
Price$0.99Free — better
Rating3.0 (5 ratings)4.5 (28 ratings) — better
Positive reviews61.0% of reviews — better0.0% of reviews
Number of ratings528 — better
Update frequencyEvery 2 monthsEvery 5 days — better
AdsNo — betterYes
In-app purchasesNo — betterYes
MonetizationPaidFree with in-app purchases — better
DevicesiPhone, iPadiPhone, iPod
Requires iOS26.014.0 — better
Further details — not scored
Size2 MB40 MB
Age rating4+4+
DeveloperDuncan CampbellNguyen Ngoc Long

Customer experience

Conversion

Written reviews41 reviews
Positive61.0%
Neutral19.5%
Negative19.5%

Battery Testing Master

All ratings19 ratings
Positive94.7%
Neutral0.0%
Negative5.3%
Written reviews2 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Conversion

No in-app purchases

1 purchases

Battery Testing Master

One-time1
  • Remove ads$1.99

Questions

Is Conversion free?
Conversion costs $0.99, with no in-app purchases.
Is Battery Testing Master free?
Battery Testing Master is free to download, with in-app purchases available.
Which has better reviews, Conversion or Battery Testing Master?
Battery Testing Master is rated higher. Conversion averages 3.0 out of 5 from 5 ratings, while Battery Testing Master averages 4.5 from 28 ratings.
Do Conversion or Battery Testing Master have ads?
Battery Testing Master shows ads; Conversion does not.
Which is updated more often, Conversion or Battery Testing Master?
Conversion ships an update every 2 months, and Battery Testing Master every 5 days. Most recently, Conversion was updated on November 10, 2026 and Battery Testing Master on November 4, 2026.

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