Comparison

Shift Calendar vs Scientific Calculator DES

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

Head to head
About

Shift Calendar

A customizable shift calendar designed for firefighters, paramedics, and EMS workers. Easily track work and off days for important personal events, supporting various common shift patterns. Includes note-taking for each shift day.

Highlights
  • Customizable shift schedules
  • Supports 24/24, 24/48, 24/72 patterns
  • Supports 48x96 pattern
  • Alpha and Numeric shift naming
  • Notes for each shift day
  • Designed for firefighters and EMS
Features
Currently charting
Read full description

Thank you for your interest in Shift Calendar, the app designed by Firefighters and built for Firefighters. Shift Calendar is the full functioning, eternal shift calendar specifically for the professional firefighter, paramedic, EMS worker, their family and friends. No more checking shift cards to see if you will be working or off on your anniversary, birthday or other important events. This version of the Shift Calendar is configurable to present shift schedules specifically for the following: 24/24 for departments working 2 platoons 24 on 24 off. 24/48 for departments working 3 platoons 24 on 48 off. 24/72 for departments working 4 platoons 24 on 72 off. For departments working more complex schedules such as 24 on and 24 off for 5 days with 96 off as A-C-A-B-A-B-C-B-C-REPEAT, look for our ShiftCal Kelley schedule app. Newly released is the popular 48x96 for departments working 3 platoons 48 on 96 off as A-A-B-B-C-C-REPEAT. Search on Cal30 to see these other options. Shift Calendar provides for both Alpha and Numeric shift naming conventions. As of version 2.0, users can now keep notes on each shift day. Future enhancements will target Kelly Day/ADO. Spread the word and pass it around. Most of all...Thank you for all you do...

About

Scientific Calculator DES

This advanced calculator offers engineers and mathematicians a powerful tool with intuitive, multi-line display and left-to-right data entry. It supports various number bases, notations, and includes extensive statistical analysis and graphing capabilities. All features are available for a one-time purchase.

Highlights
  • Multi-line display with left-to-right entry
  • Supports Hex, Binary, Octal number bases
  • Decimal, Scientific, Fractional notation
  • Angle entry in degrees, radians, gradians, turns
  • 10 Memory Registers
  • Advanced statistics and graphing
  • Import CSV files for data sets
Features
Read full description

The DES-38D is an easy-to-use, multi-line Scientific Calculator with intuitive, left-to-right data entry & display. It was designed and developed by a professional engineer with a variety of features to suit the needs of engineers and mathematicians, including extensive statistical analysis & graphing capabilities. However, it is extremely simple to use and is suitable for anyone who needs an advanced calculator. The name of the DES-38D calculator comes from the fact that it utilizes base-10 arithmetic which can represent numbers with a 38-digit mantissa and an exponent range of -128 to + 127. The DES-38D is universal app that is fully functional in both portrait and landscape modes on all iPad and iPhone devices. No need to rotate to landscape unless you need a wider display area. All current and future features are included for one low price. We will never nag you for more money. KEY FEATURES: • Supports Hex, Binary, and Octal number bases in 64-bit, 32-bit, 16-bit, or 8-bit word lengths • Accepts data entry in Decimal, Scientific, or Fractional notation (& they can be mixed) • Memory and Result data can be displayed in Decimal, Scientific, or Fractional notation independently of how the equation was entered • Angle entry and computations can be performed in degrees, radians, gradians, or turns • 10 Memory Registers • 4 Display Lines: Equations, Result, current Memory Register, and Error/Information Messages • All Display Lines read in normal human, left-to-right form • The [-] key can be used for subtraction or negation as you type - no need to use the [+/-] key after the fact (although you can) • All equations are evaluated, and the Result field is updated "on-the-fly" as you enter your formula. The [=] key merely saves the equation & result to the History/Tape file • All Equations & Results are saved in a History/Tape file • Equations & Results can be recalled from the History/Tape file for reuse in other equations • Sliders to rapidly adjust Display Precision, Decimal-to-Scientific notation switching, and Decimal to Fraction notation switching • Keys for e and π plus a table with many additional scientific and mathematical constants that can easily be included in equations • Extensive built-in help screens • Copy and paste with simple tap and long touch gestures • Use swipe gestures to rapidly display all Memory Registers at once, all Constants, and the History/Tape file • Fast and simple advanced statistics functions - simply enter a data set and instantly get over 90 statistical calculations including 8 different regressions as well as a graphic plot of the regression lines • Up to 10 Statistics Data Sets with the ability to import CSV files and print, email, or share Data Sets and Calculation Results ------------------------------- LIST OF MATH & LOGIC FUNCTIONS • Add, Subtract, Multiply & Divide (of course) • Floored and Euclidean Modulus • Percentages - including Percentage, Add-On, Discount, and Ratio calculations • Square, Cube, and nth roots • Square, Cube, and nth powers • Base-10, Base-2, Base-n, and Natural Logarithms • 24 Trigonometric Functions • Combinations & Permutations • Coordinate Conversions between Polar & Rectangular • A number of Random Number Generators to simulate coin flips, dice throws, card draws and general purpose random numbers • Reciprocals • Factorials & Double Factorials • AND, NAND, OR, NOR, XOR, XNOR, NOT • Shift and Rotate Bits * Advanced Statistics with over 90 statistics values including the results of 8 different regressions plus graphing capability ------------------------- We welcome your feedback. The app includes an email option to send comments or suggestions to us at support@dohmann.com If you enjoy our app, please rate and review us in the App Store. Thank you for using DES-38D.

Screenshots

Shift Calendar4 screens
Scientific Calculator DES4 screens

Verdict

The call

The clearest difference is rating: Scientific Calculator DES at 4.3 against Shift Calendar's 2.3. Scientific Calculator DES also leads on review sentiment (50% vs 28%). Shift Calendar's advantage is ratings volume (83 vs 3) and price ($1.99 vs $5.99). On ads, 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

Shift Calendar costs $1.99 and Scientific Calculator DES $5.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Scientific Calculator DES holds the better App Store score, 4.3 against 2.3. That said, the two scores are not equally well evidenced: Shift Calendar has 83 ratings behind it against 3, so its average is the more settled of the two. Written reviews point the same way: 28% of Shift Calendar's written reviews are positive against 50% of Scientific Calculator DES's.

UpkeepUpdate frequency

Shift Calendar ships an update fortnightly, Scientific Calculator DES every 5 weeks. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

Scorecard8 real differences · 3 level
Shift Calendar versus Scientific Calculator DES: the parameters behind the verdict, then further details
ParameterShift CalendarScientific Calculator DES
Price$1.99 — better$5.99
Rating2.3 (83 ratings)4.3 (3 ratings) — better
Positive reviews27.9% of reviews50.0% of reviews — better
Number of ratings83 — better3
Update frequencyFortnightly — betterEvery 5 weeks
AdsNoNo
In-app purchasesNoNo
MonetizationFree — betterPaid
Best chart rank#151 — better—
DevicesiPhone, iPodiPhone, iPad, iPod — better
Requires iOS8.4 — better12.0
Further details — not scored
Size1 MB9 MB
Age rating4+4+
DeveloperGil EstesDohmann Engineering Services

Customer experience

Shift Calendar

All ratings71 ratings
Positive28.2%
Neutral12.7%
Negative59.2%
Written reviews68 reviews
Positive27.9%
Neutral13.2%
Negative58.8%

Scientific Calculator DES

All ratings3 ratings
Positive66.7%
Neutral33.3%
Negative0.0%
Written reviews2 reviews
Positive50.0%
Neutral50.0%
Negative0.0%

Bugs and requests

Shift Calendar

Reported bugs

26 issues
  • Download did not complete
  • App keeps crashing
  • App does not open
  • App is inoperable after Apple update
  • App crashes when opening date and adding notes
Show 21 more
  • App disappears after iOS update
  • App not compatible with latest iOS
  • App crashes when trying to open
  • App crashes when trying to open it closes back
  • Update 14.2 made app crash
  • App will not open since last IOS update
  • App ceased working upon 14.2 iOS update
  • App will not open, crashes immediately
  • App needs to be updated to new IOS
  • App will not even open with new iPhone update
  • App needs an update
  • App crashes every time you enter a note
  • App closes every time you try to enter information
  • App closes as soon as you try to type anything in the notes
  • Crashes when I add notes
  • App shuts down when you hit the space bar
  • App will shut down when you hit the space bar
  • App crashes and does not save information
  • App crashes when entering notes for specific days
  • App crashes when hitting the return key
  • App crashes when adding notes

Requested features

14 requests
  • Accommodate 48/96 schedules
  • Support for 4 on 4 off shifts
  • Support for 5 days on, 4 days off schedules
  • Support for split shifts (2x10hrs off 24 then 2x14hrs then off for 4 days)
  • Add more shift variations
Show 9 more
  • Update Kelly Style app
  • Add built-in alarm for shift days
  • Allow multiple calendars
  • More shift color options
  • Faster month/year scrolling
  • Auto-generated payday
  • Add more custom markers (T, M, etc.)
  • Option to change pattern like Kelly shift calendar
  • Notify of scheduled events

Scientific Calculator DES

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Shift Calendar

No in-app purchases

None

Scientific Calculator DES

No in-app purchases

Questions

Is Shift Calendar free?
Shift Calendar costs $1.99, with no in-app purchases.
Is Scientific Calculator DES free?
Scientific Calculator DES costs $5.99, with no in-app purchases.
Which has better reviews, Shift Calendar or Scientific Calculator DES?
Scientific Calculator DES is rated higher. Shift Calendar averages 2.3 out of 5 from 83 ratings, while Scientific Calculator DES averages 4.3 from 3 ratings.
Do Shift Calendar or Scientific Calculator DES have ads?
Neither Shift Calendar nor Scientific Calculator DES shows ads.
Which is updated more often, Shift Calendar or Scientific Calculator DES?
Shift Calendar ships an update fortnightly, and Scientific Calculator DES every 5 weeks. Most recently, Shift Calendar was updated on November 6, 2026 and Scientific Calculator DES on November 2, 2026.

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