Calctan vs Chronographer
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Calctan
This app offers a high-precision scientific and financial calculator with an editable tape for auditing calculations. It supports complex formulas, a wide range of mathematical functions, and customizable constants, all within an ad-free, private interface.
- Smart formula workspace with direct cursor editing
- Advanced scientific engine with true order of operations
- Auditable calculation history on a digital tape
- Exportable reports via AirPrint and PDF
- Multitasking support for iPad
- iCloud synchronization across devices
- Private and ad-free experience
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Calctan is a high-precision scientific and financial tape calculator designed for iPhone and iPad. Built for students, engineers, accountants, and business professionals, Calctan bridges the gap between scientific computing and practical everyday finance. Edit complex formulas with ease, audit running totals on a printable tape, and enjoy a distraction-free workspace with no ads. KEY FEATURES 1. SMART FORMULA WORKSPACE • Direct Cursor Editing: Tap anywhere in your expression to fix numbers or operators instantly—no need to clear the expression and start over. • Live Syntax Validation: Real-time calculation preview with automatic balancing of parentheses as you type. • Fluid Multi-Line Display: Expressions scale dynamically so long formulas are never cut off. 2. ADVANCED SCIENTIFIC ENGINE • Complete Math Suite: Trigonometric functions (radians/degrees, inverse, hyperbolic), factorials, permutations, powers, roots, modulo, and logarithms. • True Order of Operations: Context-aware order of operations with high-precision calculations that minimize floating-point rounding errors. • Built-in & Custom Constants: A library covering mathematics, physics, and chemistry, plus customizable slots for your own tax rates or business ratios. 3. ACCOUNTING TAPE & REPORT EXPORT • Auditable Calculation History: Every calculation is automatically logged on a persistent digital paper tape. • Label & Categorize: Add custom notes, tags, and project labels to track expenses, homework problems, or client totals. • Batch Operations: Select multiple past entries to instantly calculate a running total. • AirPrint & PDF Reports: Generate itemized, professional calculation sheets to share, save, or print directly. 4. DESIGNED FOR PRODUCTIVITY • Multitasking on iPad: Full support for Split View, Slide Over, external keyboards, and trackpads. • iCloud Synchronization: Keep your saved formulas, constants, and calculation history unified across iPhone and iPad. • Customizable & High-Contrast Themes: Handcrafted color palettes designed to minimize eye strain during long study or work sessions. • Private & Ad-Free: No tracking, no data collection, and no subscription is required to calculate. We do not collect your data; calculations stay on your device and, if enabled, sync privately through your personal iCloud account. PERFECT FOR: • STEM & College Students: Algebra, calculus, physics, and exam prep with clear, step-by-step editing. • Finance & Accounting: Tax prep, budgeting, invoices, and expense verification with itemized tapes. • Retail & Small Business: Quick customer totals, discount percentages, and printable calculation logs.
Chronographer
This app helps you meticulously track the accuracy of your mechanical watches. It records time differences, calculates detailed performance metrics, and visualizes trends with charts and histograms. You can also manage your watch collection, log daily wear, and analyze positional variations.
- Track mechanical watch accuracy
- Calculate detailed performance metrics
- Visualize accuracy with charts and histograms
- Manage watch collection with notes and photos
- Log daily watch wear
- Analyze positional variation
- Export watch data
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Chronographer is for people who enjoy mechanical watches. It does two things: 1. Tracks your watches’ long-term accuracy 2. Records wrist time Chronographer can work with your whole watch collection. Create a “card” for each watch, giving it a name and, optionally, a longer description. Select a picture from your Photos library and add additional notes, such as the watch’s specifications, purchase details, and service history. All information is stored in iCloud and automatically synchronized between your devices. To track a watch’s accuracy, periodically collect data points comparing its indicated time to the current correct time. Chronographer tracks offsets (the difference from the correct time) and daily rate (how many seconds it gains or loses per day). It uses this information to create graphs and histograms that help you visualize your watch’s performance over time. Chronographer also calculates the following metrics: * Average offset * Max. positive offset * Max. negative offset * Last offset * Net gain/loss * Best-fit rate * Average rate * Fastest rate * Slowest rate * Last rate * Rate variance * Best-fit rate drift You can log the watch (or watches) that you wear each day. Chronographer’s wrist time tracking feature lets you see which watches you wear the most and how long it’s been since you’ve worn each one. You can use Chronographer to identify positional variation. When you record a data point, include the position (dial up, crown up, etc.) that the watch was stored in. Then, you can restrict the charts and metrics to specific positions and compare the results. Chronographer includes a large digital clock to help when you set your watches. For more information, including a detailed user’s guide, see https://www.rmfrance.net/chronographer
Screenshots
Verdict
The clearest difference is rating: Calctan at 4.5 against Chronographer's 3.4. Calctan also leads on ratings volume (61 vs 5) and iOS requirement (16.6 vs 18.6). Chronographer's advantage is in-app purchases (none vs 1) and review sentiment (50% vs 29%). On price, update cadence, ads 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
Both are free to download. Calctan sells 1 one-off in-app purchase. Chronographer asks for nothing beyond the download.
Calctan holds the better App Store score, 4.5 against 3.4. That said, the two scores are not equally well evidenced: Calctan has 61 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 29% of Calctan's written reviews are positive against 50% of Chronographer's, so the app with the better star average is not the one people write more warmly about.
Calctan ships an update every 3 months, Chronographer every 2 months. The most recent releases landed on October 29, 2026 and October 15, 2026 respectively.
| Parameter | Calctan | Chronographer |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (61 ratings) — better | 3.4 (5 ratings) |
| Positive reviews | 28.6% of reviews | 50.0% of reviews — better |
| Number of ratings | 61 — better | 5 |
| Update frequency | Every 3 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 16.6 — better | 18.6 |
| Further details — not scored | ||
| Size | 8 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Jorge Lozada | Robert France |
Customer experience
Calctan
Chronographer
In-app purchases
Calctan
- No Ads$0.99
Chronographer
No in-app purchases









