Let's see whether they are brave enough to distribute this hack (and other related ones). The DHO1000 hacking took a similar approach of decompiling and patching the executables, back in December. I keenly followed that effort, since I had a DHO1074 at the time and was hoping to see the 50 Ohm inputs and 400 MHz bandwidth enabled.
Back then, the developer(s) never made their modifications available to others and eventually pulled the plug on that effort -- due to legal concerns in my understanding. Rigol does explicitly forbid reverse engineering and decompiling in their license terms. Of course we have not seen them act on this, but who is willing to run the experiment?
Distributing patches, at least, should be legally clean. Don't quote me on this, though. Besides, there was a point about GPLed code being used in the apk. I don't know if it is so, but there seem to be a lot of standard android stuff included. Not sure what license it has.