6 devices
Available to install from
the Fitbit mobile app

Free quick access Classic calculator, with the possibility to use Reverse Polish Notation mode, Inspired by the beautiful HP41 calculator

See full documentation and release notes:

Has tactile feedback to ensure reliable calculations, and possibility to recall last input to undo last operation

Includes an optional ticker tape to show recent calculations or internal registers

Includes 4 virtual buttons shown in the display at start up

Adjustable decimal places. Whole [integer] results don't show any decimal point or places

Current operator and number of decimal places are shown on the right of the display.

4 Virtual buttons:

Clr - tap once, clears the current calculation, tap again to turn Off the App and see About information [back button will also end App]

Shft - tap to enter Shift mode, double tap to switch between RPN mode and Classic mode

Del - like Backspace, deletes last entered digit

List - tapping shows/hides the popup ticker tape, for verifying calculations, or [in Shift mod] internal registers view

Special features:

1) Negative number input: Press the 5 button and swipe Up to toggle the displayed number negative or positive.

2) Tactile feedback: Press the 5 button and swipe Left to disable or Right to enable, on by default.

3) Last operation recall:

The last operator and operand are remembered and can be applied to any displayed number by touching 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 press on = will increment the display by 1

5) Shift mode, Decimal places:

Press the virtual Shift key [above 7] followed by 1 and then a digit, 0 to 9, for the number of places required.

EG. Switch form 2 to 4 decimal places

current display 1.67

Shift, 1, 4 result 1.6700 [number previously rounded]

6) Percent calculations for working out restaurant tips





shft 2 [%]


result 27.61

7) Double tap Shft button to switch between RPN mode [see App documentation for usage] and Classic mode.

8) Closing the App

Quick close

- Press the back button

- Double tap CLR button, quick exit


- Tap twice on the CLR button, to see About and exit

- Auto closes after timeout

Recent July MMXX II - V4.2.10 (Ionic & Versa's), V5.2.10 (Sense & Versa 3)

Can also be an Addon to the free SimpleClockPro clock face, [tap Active Zone Minutes twice] see:

(Swiss made, in the land of clocks & chocolates)

From the SimpleClock / SimpleApp series =

categoryGeneral & Utilities
offered byGuy

General & Utilities

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