I will second this. I recently replaced Google maps with Leaflet.js. And as soon as I had a beta ready, and I had updated sites with the new code, I found a bet

I will second this. I recently replaced Google maps with Leaflet.js. And as soon as I had a beta ready, and I had updated sites with the new code, I found a better way to render the maps using Mapbox's own js libraries. But it doesn't matter to anyone using it. They are just glad to be rid of Google maps, right now. If there's another small hurdle, they don't mind. And if I make improvements down the road, all the better. You can always add the "convenience" of in-app billing later. A nice upgrade that will make your users happier. :) Or, as I have often found, you may decide to _never_ put billing into your app. Why? Because you may learn that your users' are just fine with paying via your website instead. But you would only find this out by launching now, and talking with your clients.