I still don’t get what problem MobileCoin solves that Monero doesn;t.
I think the only crypto that actually makes sense for payments is Monero as it’s the only private coin, has very low transfer fees, and has been around for a long time.
Add Bitcoin or Litecoin for on/offramping (as many exchanges don’t list Monero due to regulatory pressure) and that’s all I’d ever need.
Cake Wallet is nice and supports these three coins although you can’t directly buy Monero, you have to buy e.g. Litecoin and then exchange it to Monero (all can be done in the app)