Comparison

CCCSeries2 Catechism vs Calvin Opera

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

Head to head
About

CCCSeries2 Catechism

Access the complete Catechism of the Catholic Church and all Vatican II documents directly from the Vatican website. This reference tool is organized for easy navigation through its four main sections: Beliefs, Sacraments, Morality, and Prayer.

Highlights
  • Complete Catechism of the Catholic Church
  • All Vatican II documents
  • Direct Vatican website links
  • Organized by topic
  • Smooth navigation
  • Summary of Second Vatican Council
Features
Read full description

The Ultimate Catholic Reference Guide Deepen your faith and study with the absolute gold standard of Catholic teaching. The CCCSeries App brings you the ENTIRE Catechism of the Catholic Church and ALL 16 Vatican II documents, streaming instantly and securely directly from the official Vatican website. As St. John Paul II declared, the Catechism is "a sure and authentic reference text for teaching Catholic doctrine." This app is your gateway to that truth. Why This Is the BEST Reference Tool Available: 100% Authentic Sourcing: Every text connects directly to the Vatican website inside the app, ensuring absolute fidelity to the Magisterium while strictly adhering to USCCB copyright laws. All-In-One Library: Access the complete Catechism, all 16 Vatican II documents, plus an exclusive summary explaining the Council’s purpose, history, and real-world implementation. Flawless Navigation: Experience a beautiful, smooth, and highly intuitive user interface designed for effortless study, reading, and contemplation. Perfect for Everyone: An essential companion for home-schoolers, Catechists, CCE teachers, college students, seminarians, and anyone seeking theological truth at their fingertips. Perfectly Organized for Seamless Study: The Catechism: Divided into the four pillars of faith—Beliefs, Sacraments, Morality, and Prayer—and meticulously sub-categorized by topic. Vatican II Documents: Cleanly grouped into the Council's official Constitutions, Declarations, and Decrees for rapid reference. Important Usage Notes: Internet Connection Required: To comply with Holy See copyright guidelines and keep text verification authentic, a Wi-Fi or cellular internet connection is required to open the Vatican links. Academic Use: Exemptions apply for academic discourse (dissertations, scholarly articles, and course materials) provided all citations are properly acknowledged.

About

Calvin Opera

Access the complete writings of John Calvin with fast search capabilities and an integrated Latin dictionary. This comprehensive collection is a primary resource for studying Calvin's extensive theological works.

Highlights
  • Complete Works of John Calvin
  • Fast search functionality
  • Integrated Latin dictionary
  • Primary source for Calvin studies
  • Organized by volume and content type
Features
Read full description

The ‘Complete Works of Calvin’ refers to ‘Ioannis Calvini opera quae supersunt omnia’ (‘All Surviving Works of John Calvin’), which were edited between 1863 and 1900 by Johann Wilhelm Baum, August Eduard Cunitz and Eduard Reuss, and were published in 59 volumes. As the title indicates, it is a collection of all the writings of Calvin which had survived up to that time. The ‘Complete Works of Calvin’ is commonly abbreviated to ‘CO’(Calvini Opera), but is also abbreviated to ‘CR’ because it forms vols. 29-87 of the ‘Corpus Reformatorum,’ which also includes the works of Reformers Philip Melanchthon and Huldrich Zwingli. Thus, the first volume of the ‘Complete Works of Calvin’ can be referred to as ‘CO 1’ or ‘CR 29.’ The ‘Complete Works of Calvin’ remains the best primary source for the study of Calvin. Since 1992, critical editions of Calvin’s works have been published, starting with ‘Opera Exegetica: Commentarii in Pauli Epistolas ad Galatas, ad Ephesios, ad Philippenses, ad Colossenses,’ ed. Helmut Feld (Geneva: Librairie Droz, 1992). This task is being undertaken by an international committee of members of the finest quality, affiliated with the International Congress on Calvin Research. The contents of the ‘Complete Works of Calvin’ are as follows: Vols. 1-4 contain the Institutes of the Christian Religion, Vols. 5-9 mainly short treatises, 10-20 Epistles, 21 the lives of Calvin, 22 the indices of vols. 1-21, 23-44 Old Testament commentaries and sermons, 45-55 New Testament commentaries and sermons, 56-57 Calvin’s French Bible, 58-9 additional sermons and indices to vols. 23-55. This App enables fast searches of the ‘Complete Works of Calvin’ and contains an easy-to-use Latin dictionary. This is the combined works of two organizations, PartPrime and KIRS(Korean Institute for Reformed Studies).

Screenshots

CCCSeries2 Catechism4 screens
Calvin Opera4 screens

Verdict

The call

The clearest difference is price: CCCSeries2 Catechism at $1.99 against Calvin Opera's $15.99. CCCSeries2 Catechism also leads on rating (2.3 vs 1.0) and ratings volume (7 vs 1). On update cadence, ads, in-app purchases and monetization model 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

CCCSeries2 Catechism costs $1.99 and Calvin Opera $15.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

CCCSeries2 Catechism holds the better App Store score, 2.3 against 1.0. That said, the two scores are not equally well evidenced: CCCSeries2 Catechism has 7 ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

CCCSeries2 Catechism ships an update every 5 months, Calvin Opera every 9 months. The most recent releases landed on October 24, 2026 and October 7, 2026 respectively.

Scorecard3 real differences · 7 level
CCCSeries2 Catechism versus Calvin Opera: the parameters behind the verdict, then further details
ParameterCCCSeries2 CatechismCalvin Opera
Price$1.99 — better$15.99
Rating2.3 (7 ratings) — better1.0 (1 ratings)
Positive reviews16.7% of reviews—
Number of ratings7 — better1
Update frequencyEvery 5 months — betterEvery 9 months
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS15.014.0 — better
Further details — not scored
Size25 MB1.6 GB
Age rating4+4+
DeveloperBil Kimesjeong youngoh

Customer experience

CCCSeries2 Catechism

All ratings7 ratings
Positive28.6%
Neutral0.0%
Negative71.4%
Written reviews6 reviews
Positive16.7%
Neutral0.0%
Negative83.3%

Calvin Opera

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

CCCSeries2 Catechism

No in-app purchases

None

Calvin Opera

No in-app purchases

Questions

Is CCCSeries2 Catechism free?
CCCSeries2 Catechism costs $1.99, with no in-app purchases.
Is Calvin Opera free?
Calvin Opera costs $15.99, with no in-app purchases.
Which has better reviews, CCCSeries2 Catechism or Calvin Opera?
CCCSeries2 Catechism is rated higher. CCCSeries2 Catechism averages 2.3 out of 5 from 7 ratings, while Calvin Opera averages 1.0 from 1 ratings.
Do CCCSeries2 Catechism or Calvin Opera have ads?
Neither CCCSeries2 Catechism nor Calvin Opera shows ads.
Which is updated more often, CCCSeries2 Catechism or Calvin Opera?
CCCSeries2 Catechism ships an update every 5 months, and Calvin Opera every 9 months. Most recently, CCCSeries2 Catechism was updated on October 24, 2026 and Calvin Opera on October 7, 2026.

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