New Acron RPN Calculator for Android

[rprosperi]

I agree, this is a very interesting design, rather different from most I've seen. All the green keys bring up menus of (mostly) related functions.

Separate trig functions for degree and radian modes is unique, it will take some time using it to see if this is a positive or negative.

The stack seems to be unlimited (or perhaps just rather high, 10 at least) and there are several functions for juggling the stack like SWAP (2) Roll 3 (up and down) and Roll 4 (up and down).

Entering a calculation whose result can be expressed as a proper fraction is shown that way, so 89 [ENTER] 3 [*] 100 [/] is displayed as 267 / 100 with 2.67 seen in parenthesis).

It seems to have a fairly wide numeric range, appears to be 10^-324 to 10^308.

I have not had a chance to explore precision levels yet, but some odd things happen, e.g. entering 10 E-324[ENTER] yields 9.88131281682493 E-324.

Also, 2 [ENTER] 3 [/] => 6.6666666664833 E-7.

The [<=] key to backspace the current entry is very close to the currently open menu so it's easy to hit a function instead of the backspace, however this is nicely offset by the undo key.

The primary thing I find missing from the feature set is any kind or storage or memory register. Since it's not programmable, not too many are needed, but having at least one would be useful.

An unexpected feature, or perhaps bug, is the status of the stack is not maintained between sessions.

Quite interesting design. I agree it feels somewhat slow, however my phone is also somewhat old so perhaps this is the cause. That said, I do not have the same lag on FREE42 or other calculator Apps.

Users interested in new/different designs should definitely check this out.