![Grin](https://bitcointalk.org/Smileys/default/grin.gif)
Monero seems like a good option, (maybe ripple? but ONLY maybe) but otherwise...
I'm highly suspicious of ripple, btw.
Focus on coin that has good wallet support for both ios and android phones. Until you have wallets supported by both ios and android, I would suggest you're still small fish.
*Flamesuit on*
There are plenty of interesting cryptos out there but how many do you want to admin on faucethub? That's why I suggest to focus on the big actors, less speculation that way.
I like speculation as much as the next man, but I don't know if it's the right thing for faucethub?