Reddit's /r/emulation board has become rather interested in these sorts of games over the past few days, which in turn re-sparked my own search for some of them. I've found this website, seemingly a Chinese fan page dedicated to the Shin Megami Tensei game series. If you CTRL+F for ".jar", you'll see there's two files with the title "Shin Megami Tensei.jar". The text above these links translates to something like "Two .jar files of unknown origin". Unfortunately, both the download links for these files are dead. I've checked the internet archive as well but sadly they don't have them saved. I'm posting it here on the off chance someone might be able to contact the site owner and ask for the files/ask them to reupload the files to the site. They could just be nothing, but it's killing me that we might not find out what they are. Also for anyone who hasn't seen it yet, there's a new emulator for these sorts of mobile games called FreeJ2ME. It's quite compatible already so definitely seems worth a look!