APL

For android and apl we also have dzaima's AndroidIDE which is the best android array implementation that I have found. https://github.com/dzaima/APL/tree/master/AndroidIDE

https://github.com/dzaima/APL has an Android app with a virtual APL keyboard. I believe you can find the apk under "releases".

> Admittedly the J implementation at least of deriving a generalized inverse for an arbitrary function f is a somewhat ill-defined hack Have you seen the version used by dzaima/apl[1]? The equivalent of '(-&.:{:) i.5' works and results in 0 1 2 3 _4. > APL has some really dumb but cherished-by-the-community ideas that make the language less expressive and much more awkward to learn, e.g. the idea of replicating the terrible defect of normal mathematical notation where - is overloaded for negation and subtraction to every other function Klong[2] is a partial attempt to resolve this. I won't repeat the arguments in favour of ambivalent functions, as I guess you've heard them a dozen times before > u(f,g) = x => f^-1(g(f(x)). Other way round; it's g^-1(f(g(x))) 1. https://github.com/dzaima/apl 2. https://t3x.org/klong/

dzaima/APL (https://github.com/dzaima/apl) has an Android version. I would recommend that over GNU APL which makes a number of questionable language choices. Many modern APLs—Dyalog APL, NARS2000, ngn/apl, and dzaima/APL—include support for forks. They're usually called function trains in APL.

dzaima/APL is implemented in Java and can be built as an Android app; steps in the readme here: https://github.com/dzaima/APL and downloadable APK and screenshots here: https://github.com/dzaima/APL/tree/master/AndroidIDE (I think; I've never used it)