The Logic Calculator vs HTML Viewer Pro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
The Logic Calculator
This free utility app helps users perform propositional logic operations with ease. It provides detailed feedback on input well-formedness, sentence types, set consistency, and argument validity. Users can also generate and copy truth tables to other applications.
- Propositional logic operations
- Input well-formedness checking
- Tautology, contradiction, and contingency determination
- Set consistency checking
- Argument validity checking
- Truth table generation
- Copyable truth tables
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This free app allows users of propositional logic to perform operations with the same ease as that offered by a mathematical calculator. It facilitates learners of logic by providing considerable feedback. To be precise, using this app, one can determine whether: (1) input is well-formed and, if not, why not, (2) sentences are tautologies, contradictions or contingent, (3) sets of sentences are consistent or inconsistent and (4) arguments are valid or invalid. It also produces truth tables which can be copied into other applications. As of this version, the calculator is restricted to semantic operations.
HTML Viewer Pro
View HTML source code from URLs or directly from Safari. This app offers multi-tab browsing, bookmarking, and search functionality. Customize the display with various themes, fonts, and user agents.
- View source code from URLs
- View source code from Safari share
- Multi-tab browsing
- Bookmark and history management
- Keyword search in source code
- Switch between static and dynamic HTML
- Customizable themes and fonts
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It is a multi-functional HTML source viewer. You can view the source code by URLs, and of course, you can also view the source code from Safari's share button. Since it is the latest version of the app, it covers almost all the features of other apps. [Features & Functions] - Browser and source code switching. - Multi-tab browsing. - Display bookmarks and history. - Search for keywords in the source code. - Switch between static and dynamic HTML. - Changing the user agent. - Display non-HTML languages. - Use the cloud, such as iCloud, Dropbox, OneDrive, etc. - Use local files in the iPhone and iPad. - Balanced light operation. [View source code] - About 90 different design themes available. - Change the font, size and line spacing. - Switch between static and dynamic HTML. - Support for almost all programming languages (over 180). [Terms & Conditions] https://www.hayaya.net/terms-conditions/html-viewer.html [Privacy Policy] https://www.hayaya.net/privacy-policy/html-viewer.html
Screenshots
Verdict
The clearest difference is review sentiment: The Logic Calculator at 100% against HTML Viewer Pro's 49%. The Logic Calculator also leads on rating (4.4 vs 3.9) and in-app purchases (none vs 2). HTML Viewer Pro's advantage is ratings volume (45 vs 7). On price 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. HTML Viewer Pro sells 2 in-app purchases, starting at $1.99 per month. The Logic Calculator asks for nothing beyond the download.
The Logic Calculator holds the better App Store score, 4.4 against 3.9. That said, the two scores are not equally well evidenced: HTML Viewer Pro has 45 ratings behind it against 7, so its average is the more settled of the two. Written reviews point the same way: 100% of The Logic Calculator's written reviews are positive against 49% of HTML Viewer Pro's.
The Logic Calculator ships an update every 5 weeks, HTML Viewer Pro every 15 months. The most recent releases landed on September 26, 2026 and October 10, 2026 respectively.
| Parameter | The Logic Calculator | HTML Viewer Pro |
|---|---|---|
| Price | Free | Free |
| Rating | 4.4 (7 ratings) — better | 3.9 (45 ratings) |
| Positive reviews | 100.0% of reviews — better | 49.1% of reviews |
| Number of ratings | 7 | 45 — better |
| Update frequency | Every 5 weeks — better | Every 15 months |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 9.0 — better | 12.0 |
| Further details — not scored | ||
| Size | 30 MB | 33 MB |
| Age rating | 4+ | 17+ |
| Developer | Ioannis Votsis | Hayato Shimizu |
Customer experience
The Logic Calculator
HTML Viewer Pro
In-app purchases
The Logic Calculator
No in-app purchases
HTML Viewer Pro
- Premium (Monthly plan)$1.991 Month
- Premium (Buying out)$19.99
Questions
Is The Logic Calculator free?
Is HTML Viewer Pro free?
Which has better reviews, The Logic Calculator or HTML Viewer Pro?
Do The Logic Calculator or HTML Viewer Pro have ads?
Which is updated more often, The Logic Calculator or HTML Viewer Pro?
Other comparisons
