I've done exactly that - integrated Stripe with our Firebase-backed app (https://play.google.com/store/apps/details?id=com.twansoftware.invoicemakerpro&hl=en ht

I've done exactly that - integrated Stripe with our Firebase-backed app (https://play.google.com/store/apps/details?id=com.twansoftware.invoicemakerpro&hl=en https://play.google.com/store/apps/details?id=com.twansoftwa...). My method was to use App Engine as the callback component to handle Stripe webhooks. I also do have custom server code, which was a little bit tough to get going, but it's great having a dedicated Linux box as well.