2-way communication with Android app (through intent?)

Hey everyone,

I'm the developer of Catima, an Open Source loyalty card app for Android. People have been asking for WearOS support, but I am kinda not looking forward to supporting only proprietary platforms, so I've been trying to figure out if I can support Bangle.js instead.

Specifically, I want to support getting a list of your loyalty cards and when clicking a card show the barcode. This would need at least some kind of 2-way communication and I was wondering if it's possible to:

1. Either send a result to an intent back to Bangle.js (so you could start an intent for GET_CARD_LIST and do something with that data)
   
2. Or send data through intents to Bangle.js through Gadgetbridge asynchronously by calling some intent that will make Gadgetbridge forward data to Bangle.js
   
3. Do something completely different altogether
   
   

Is this possible? And if data is sent back somehow, is it possible to send an image file back so that the Bangle.js won't need any code to render barcodes itself?

Thanks in advance for any answer :)

P.S.: Is there any reason why the forum doesn't have a valid SSL certificate? Could this be fixed by any chance?