I'm interesting too. I did a ADF application, and I studied ADF Mobile and now I'm starting with MAF. I know JDE MAF applications has JDE libraries and we need AIS Server (or MCS probably), but I have to study and investigate it.
I helped write a couple of proof-of-concept applications in MAF and *would not* recommend them.
I think you would be better off using something like Apache Cordova to build your mobile app. For connecting into JDE you should look at AIS integration or the XML CallObject API.
All of these options are free and superior to MAF, in my opinion..