- **Stellar:** Stellar Lumens (XLM) is designed for cheap a…

- **Stellar:** Stellar Lumens (XLM) is designed for cheap and fast cross-border transactions, which can be seen as "X" payments in a broad sense.

- **Nano:** It's a feeless, instant payment blockchain where each account has its own blockchain, potentially fitting the bill for "X" if we're looking for a more simplified, direct payment system.