Comparison

Black Box vs KCalc Lock

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

Head to head
About

Black Box

Secure your phone by locking and restricting access to sensitive applications. Protect your private data with advanced password protection and prevent unauthorized app usage or in-app purchases. Enjoy comprehensive digital privacy with an easy-to-use interface.

Highlights
  • App locking with password protection
  • App disappearance for hidden access
  • App usage restrictions
  • Secure privacy with advanced passwords
  • Payment locking for in-app purchases
  • Intuitive interface
Features
Read full description

Black Box: Easily lock and restrict apps, protect your private data with one click. Secure your phone with a password. 100% safe and private! Don't want others to see your privacy? Use our lock and restrict features to keep your apps and data hidden from others. Try this most secure app lock and give your phone 100% privacy protection. 【Key Features】 App Locking: Set password protection for sensitive apps like social media, photo galleries, etc., protecting your privacy anytime, anywhere. App Disappearance: No one but you can find your apps unless you actively reveal them. App Restrictions: Limit app installation, deletion, in-app purchases, control app visibility everywhere, and lock app usage. Secure Privacy: The app lock features advanced security passwords, helping you lock apps and prevent others from casually viewing in-app data. Payment Locking: Lock App Store in-app purchases to avoid accidental payments or prevent your children from buying games. 【Why Choose Black Box?】 100% Safe and Reliable: Uses advanced encryption technology Easy to Use: Intuitive interface design, effortless to get started Comprehensive Protection: Guards your privacy from apps to files Continuous Updates: We constantly improve features to provide you with the best experience Download Black Box now and enjoy true digital privacy! Your encouragement drives our progress! Stay tuned for more powerful features coming soon. If you encounter any issues or have suggestions while using the app, please feel free to provide feedback within the app. blackbox@whohub.cn Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://blackbox.whohub.cn/policy/privacy Use the most reliable app lock to protect your privacy, easily safeguard your digital privacy. Use the app lock to lock apps or protect apps from being discovered, ensuring your security.

About

KCalc Lock

Secure your personal data with multi-layered protection. Lock sensitive apps, photos, and files using passwords or biometrics. Features include one-tap protection, a private photo vault, and a dual privacy shield for enhanced security.

Highlights
  • Password & Biometric Protection
  • One-Tap App Protection
  • Private Photo Vault
  • Customizable App Icon
  • Dual Privacy Shield (Guest Passcode)
Read full description

KCalc – Your Fully Private & Secure Space With KCalc Privacy Lock, your personal data is protected by multi-layered security. No more worrying about friends or colleagues accidentally accessing your secret apps, photos, or files. • Password & Biometric Protection Secure your space with a strong password or unlock seamlessly via Face ID. • One-Tap Protection Instantly protect sensitive apps with a single tap. Enable the auto-lock feature for enhanced convenience and security. • Private Photo Vault Safely store confidential photos in an encrypted gallery, safeguarded from prying eyes. • Custom App Icon Personalize the app icon to match your style. Choose from multiple icon options for a truly private and personalized experience. • Dual Privacy Shield When asked to unlock under scrutiny, enter the guest passcode to instantly switch to Second Space — your private data stays fully hidden while showing pre-set content. Download KCalc Privacy Lock now and take full control of your digital privacy — fast, smart, and secure. Pro Subscription Information KCalc offers an auto-renewable Pro subscription (monthly). Subscribing unlocks all Pro features in the app. - Payment: Payment will be charged to your Apple Account at confirmation of purchase. - Auto-Renewal: Your subscription automatically renews unless auto-renew is turned off at least 24 hours before the end of the current period. Your account will be charged for renewal within 24 hours prior to the end of the current period. - Manage or Cancel: You can manage your subscription and turn off auto-renewal at any time in Settings → tap your name → Subscriptions. Terms of Use: https://dawn-zephyr-0e3.notion.site/Terms-of-Use-End-User-License-Agreement-3dc70fc5aff880d382dcca2c6441df51 Privacy Policy: https://dawn-zephyr-0e3.notion.site/Private-Policy-3dc70fc5aff880e783aed858da8eaad2 Feedback & Support: aiseaystudio@gmail.com

Screenshots

Black Box4 screens
KCalc Lock4 screens

Verdict

The call

The clearest difference is in-app purchases: Black Box at none against KCalc Lock's 2. KCalc Lock's advantage is review sentiment (97% vs 67%). On price, rating, ratings volume and update cadence 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. KCalc Lock sells 2 in-app purchases, starting at $5.99 per month. Black Box asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Black Box holds the better App Store score, 4.7 against 4.5. Both are backed by a comparable volume of ratings — 41 and 45 respectively. Written reviews complicate that: 67% of Black Box's written reviews are positive against 97% of KCalc Lock's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 3 days. The most recent releases landed on October 24, 2026 and October 27, 2026 respectively.

Scorecard2 real differences · 8 level
Black Box versus KCalc Lock: the parameters behind the verdict, then further details
ParameterBlack BoxKCalc Lock
PriceFreeFree
Rating4.7 (41 ratings) — better4.5 (45 ratings)
Positive reviews66.7% of reviews97.1% of reviews — better
Number of ratings4145 — better
Update frequencyEvery 3 daysEvery 3 days
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhoneiPhone, iPad — better
Requires iOS16.016.0
Further details — not scored
Size68 MB33 MB
Age rating4+4+
Developer俊涛 刘海芸 吴

Customer experience

Black Box

All ratings37 ratings
Positive91.9%
Neutral5.4%
Negative2.7%
Written reviews9 reviews
Positive66.7%
Neutral0.0%
Negative33.3%

KCalc Lock

All ratings44 ratings
Positive88.6%
Neutral2.3%
Negative9.1%
Written reviews34 reviews
Positive97.1%
Neutral0.0%
Negative2.9%

In-app purchases

None

Black Box

No in-app purchases

2 purchases

KCalc Lock

Subscriptions1
  • Pro Monthly$5.991 Month
One-time1
  • Pro Lifetime Access$39.99

Questions

Is Black Box free?
Black Box is free to download, with no in-app purchases.
Is KCalc Lock free?
KCalc Lock is free to download, with in-app purchases available.
Which has better reviews, Black Box or KCalc Lock?
Black Box is rated higher. Black Box averages 4.7 out of 5 from 41 ratings, while KCalc Lock averages 4.5 from 45 ratings.
Do Black Box or KCalc Lock have ads?
Neither Black Box nor KCalc Lock shows ads.
Which is updated more often, Black Box or KCalc Lock?
Black Box ships an update every 3 days, and KCalc Lock every 3 days. Most recently, Black Box was updated on October 24, 2026 and KCalc Lock on October 27, 2026.

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