You got it all, tho not completely sure iPhone applet install support.
Maybe wanna consider a backup of some sort for some/all things possible, maybe a yubikey neo nfc or a fidesmo card.
I mean I haven’t looked at it but I’m willing to bet it’s non obfuscated java, so easily decompiled. But then you would probably find that the writing logic id all done on the server and it is basically sending APDUs to the Apex which you’d have to look at then.
This all should fail as you do not have the masterkey fidesmo has, so installing applets locally wont work.
If you have a fidesmo dev acc you can use the fsdm cli tool to install applets from linux.