The sAPL program provides a P/C version of the original IP Sharp mainframe APL.  I bought the P/C version directly from IP Sharp, and it came with a license that allowed it to be offered freely to anyone, as a product for APL teaching and learning.  The P/C version - sAPL - runs by means of an emulator that executes IBM 370 machine code.  So, the Android sAPL version is basically an emulator (sAPL) running on an emulator (IBM machine code), running on an emulator (gDOSbox), running on an emulator (ART - Android Run-Time, the replacement for the Dalvik machine, which powers Android Kitkat 4.x tablets and devices).

The sAPL package can be run on Android under gDOSbox, iPad under DOSpad, on Windows machines in any Cmd shell (or DOSbox, if you want), and on Linux under DOSemu (tested using Fedora and CentOS 6.6). 

What is interesting is how well it works.  The images on the top-line sub-menu are from the IP Sharp APL "Guide Sheet" or sAPL cheat-sheet.   Hope this is useful for APL users!