I am working on a way to use web bluetooth to configure WiFi on Argon devices in the field. The advantage of web bluetooth is you don't have to publish a mobile app -- you can add the code to any web page and you simply browse to the web site to get the "app." Works great on Android and MacOS. The downside is that safari on iOS does not support web BT (last time I checked), so you have to purchase a special browser to get webBT:
I posted a little information in this thread with my current solution:
Note, it still needs some polish (security, etc), but the basics work.
I don't consider the particle app a production solution as it does not seem to work once a device is part of a product, and using the barcode on the device is not very convenient if it is in an enclosure. I'm also not sure how your customers could use it (can they have separate accounts, etc). (correct me if I'm wrong about this).
What I need is mobile experience where you can scan for all devices locally, select one from a list, perhaps enter a password, and then be able to configure it, view diagnostic info, etc.