Comparison

Engineering Calculator vs Speaker Booster

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

Head to head
About

Engineering Calculator

This utility app helps users convert units and calculate tips, primarily for those in the US. It operates offline and aims for minimal user interaction to provide quick results. Useful for avoiding misunderstandings in business dealings due to unit differences.

Highlights
  • Unit conversion
  • Tip calculation
  • Offline functionality
  • Minimalist interface
  • Business negotiation aid
Features
Read full description

米国(アメリカ)で生活するエンジニアのための単位換算、チップ計算ができるアプリです。 特にエンジニアである必要もないですが。。。 オフラインで動作可能、広告もありません。 極力少ない操作で結果が出るようになっています。 米国企業などと商談を行うときには単位の相違によって誤解が生じることが多々あります。 このアプリを使って手早く単位変換ができれば、早く理解出来、結果商談の成功に繋がります。

About

Speaker Booster

Enhance the volume and clarity of your imported audio files, including music, podcasts, and recordings. Features a powerful equalizer with presets for different audio types and a digital gain of up to +24 dB. Enjoy background playback with lock screen controls.

Highlights
  • Volume boost up to +24 dB
  • Built-in limiter for distortion-free audio
  • Live level meter and spectrum animation
  • Vocal, Bass, and Podcast EQ presets
  • 10-band manual equalizer with custom presets
  • Import MP3, WAV, M4A, FLAC, AAC
  • Extract audio from MP4 videos
  • Background playback with lock screen controls
Features
Read full description

Volume maxed out and still hard to hear? Ampcrank is an audio-boosting player: import your music, podcasts, recordings, and voice messages, then make them louder and clearer with real volume gain and a full equalizer. VOLUME BOOST - 0 to +24 dB digital gain — turn the knob and hear the difference instantly - Built-in limiter keeps audio clean and distortion-free even at maximum boost - Live level meter and spectrum animation show the boost at work EQUALIZER - Vocal Booster: brings muffled, unclear speech into focus - Bass Boost: deeper, punchier low end - Podcast / Voice Memo: tuned for recordings and voice messages - 10-band manual EQ (31 Hz–16 kHz) with savable custom presets A COMPLETE LOCAL PLAYER - Import MP3, WAV, M4A, FLAC, and AAC from the Files app or iCloud Drive - Extract the audio track from MP4 videos - Receive audio files shared from other apps via the system share sheet - Background playback with Lock Screen and Control Center controls CLEAN AND SIMPLE - No account required; your audio files stay on your device and are never uploaded HOW IT WORKS Ampcrank enhances audio through digital signal processing (gain + EQ + limiting) applied to files played inside the app. It does not raise your iPhone speaker's hardware volume limit, and it does not amplify other apps, ringtones, or phone calls. AMPCRANK PRO - Boost audio all the way to +24 dB - Use the full 10-band equalizer - Unlock every preset, custom presets, and loop mode - Payment is charged to your Apple ID. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period. Manage or cancel in App Store settings. This app is using the standard Apple Terms of Use (EULA) https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

Engineering Calculator1 screens
Speaker Booster3 screens

Verdict

The call

The clearest difference is rating: Speaker Booster at 5.0 against Engineering Calculator's 4.5. Speaker Booster also leads on ads (none vs shown) and update cadence (fortnightly vs monthly). Engineering Calculator's advantage is monetization model (ad-supported vs freemium) and iOS requirement (12.2 vs 15.0). On price, ratings volume, 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Speaker Booster holds the better App Store score, 5.0 against 4.5. Both are backed by a comparable volume of ratings — 2 and 2 respectively.

UpkeepUpdate frequency

Engineering Calculator ships an update monthly, Speaker Booster fortnightly. The most recent releases landed on October 9, 2026 and October 24, 2026 respectively.

Scorecard5 real differences · 4 level
Engineering Calculator versus Speaker Booster: the parameters behind the verdict, then further details
ParameterEngineering CalculatorSpeaker Booster
PriceFreeFree
Rating4.5 (2 ratings)5.0 (2 ratings) — better
Number of ratings22
Update frequencyMonthlyFortnightly — better
AdsYesNo — better
In-app purchasesNoNo
MonetizationAd-supported — betterFreemium
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS12.2 — better15.0
Further details — not scored
Size1 MB14 MB
Age rating4+4+
DeveloperMasato Kanazawa明航 李

Customer experience

Engineering Calculator

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Speaker Booster

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Engineering Calculator

No in-app purchases

None

Speaker Booster

No in-app purchases

Questions

Is Engineering Calculator free?
Engineering Calculator is free to download, with no in-app purchases.
Is Speaker Booster free?
Speaker Booster is free to download, with no in-app purchases.
Which has better reviews, Engineering Calculator or Speaker Booster?
Speaker Booster is rated higher. Engineering Calculator averages 4.5 out of 5 from 2 ratings, while Speaker Booster averages 5.0 from 2 ratings.
Do Engineering Calculator or Speaker Booster have ads?
Engineering Calculator shows ads; Speaker Booster does not.
Which is updated more often, Engineering Calculator or Speaker Booster?
Engineering Calculator ships an update monthly, and Speaker Booster fortnightly. Most recently, Engineering Calculator was updated on October 9, 2026 and Speaker Booster on October 24, 2026.

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