Doesn't it say it's a java app?
Before you can run MrPostman you need a JVM (Java Virtual Machine) installed, version 1.4+
I know little about the Z's Java implementation, is it up to this level?
Si
It depends on your Z model. Certainly the 5600 and older models do not have this version of Java (or equivalent). Not sure about the others.
In any case I would think that porting
Hotway should not be too much of a problem.