Fitbit SimpleCalculator Operations
(last update 2022-07-18 Version 4.2.10- Version 5.2.10 [Versa 3 & Sense])
Quick Guide Overview
For quick access, a
great simple Classic calculator, inspired by the beautiful HP-41
Tactile feedback On or Off is shown on the left of the display.
Can do constant calculations, including percentages, for tips
Can also work in Reverse Polish Notation mode like the original HP-41
Tap once, clears the current calculation,
Tap again to see About information and Close the App.
Double tap to do quick close. [The back button will also Close the App]
The App will auto close after a time of no activity.
2) Shft - Shift key, above the 7 key
Tap to enter Shift mode [works with buttons with gold writing above]
Tap a second consecutive time to switch back and forth between Classic and RPN calculation mode
(New: Calculation mode is retained between use)
3) Del - Above the 8 key
like Backspace, deletes last entered digit
4) List -Above the 9 key
Tapping shows/hides the popup ticker tape list, for verifying calculations
Tap Shft before List to get a transparent pop up of the calculation registers
1) Negative number input:
Tap the 5 button and swipe Up to toggle the displayed number negative or positive.
2) Tactile feedback:
Tap the 5 button and swipe Left to disable or Right to enable. A bell indicator on the left of the display shows state
3) Last operation recall:
The last operator and operand are remembered and can be applied to any displayed number by pressing on =, entering a new calculation clears this function.
3 + 6 = result 9
5 = result 11
2 = result 8
4) Counter mode:
Enter + 1 = [result 1], each subsequent tap on = will increment the display by 1
5) Shift mode, Decimal places:
Tap the virtual Shift key [above 7] followed by 1 and then a digit 0 to 9 for the number of places required.
EG. Switch from 2 to 4 decimal places
current display 1.67
Shift 1 4, result 1.6700 [number previously rounded]
6) Shift mode, Pi:
Tap the virtual Shift key [above 7] followed by 0 and Pi will be entered in the display
To add 12% tip - to 25.10
Shft 2 [%]
result = 28.11
Tap Shft 2 consecutive times to switch back and forth between Classic and RPN calculation mode.
[In RPN mode, Enter is shown instead of =]
1) Tap List to get a transparent pop up of the calculations ticker tape
2) Tap Shft before List, to get a transparent pop up of the calculation registers
HP-41C and Reverse Polish Notation aficionado's references:
2) HP41C manual
3) Original HP-41C 
The first programmable calculator, HP-65 , was used in space. It had a magnetic card reader incorporated for storing and reading programs or data into memory.
Later the upgraded HP-67
 was produced then the switch from red led display to LCD in the
form of the HP-41C saw production in 1979, which also had connectable card reader, printer and memory modules.
Calculator releases (V4 - Ionic & Versa's, V5 - Sense, Versa 3)
Vx.2.10 - 2022-07-19
Vx.2.09 - 2021-09-13
Vx.2.08 - 2021-08-10
Vx.1.16 - 2021-06-13
Vx.1.15 - 2021-06-06