Today's Android devices are powerful enough to run circles around most game consoles of yesteryear, but that doesn't mean emulating old hardware is easy. 2D games, sure, walk in the park—but replicating the original PlayStation is a different thing entirely. Nevertheless, that hasn't stopped an Android developer from trying to tackle the even more powerful PlayStation 2.
Play!, as the emulator is called, also supports Windows, Mac OS X, and iOS. Here's a video of an Android tablet running Final Fantasy X. Though they aren't demonstrated, we can see that the tester also has Capcom Vs SNK 2, Dragon Quest VIII, Dynasty Warriors 2, Gradius V, Kingdom Hearts, and Space Harrier saved to the device.
Maybe you don't want to spend thirteen minutes watching the video, so here's the tl;dw. The current experience is very laggy, and much of the text is garbled. Load times will test your patience. In its current form, you won't have any fun trying to play this game.
But Play! for Android is still in very early development, and it's no small feat to see Final Fantasy X running at all. The Dolphin Gamecube emulator, despite coming along rather nicely, still has its share of issues to work through as well. PPSSPP for the PlayStation Portable is further along.
If you aren't scared off by the bugginess, you can play around with Play! for yourself. To get started, go join the Google+ community. Then head back to the Play Store to enter the testing program. After that, you can view the Play Store page and download the goods. Just in case you run into issues, the APK's also available on APK mirror.