Unfortunately, Apple does not allow video game emulators in their App Store. Emulators do exist for Apple products, but you must perform a jailbreak to gain access to them. For security reasons, I do not recommend jailbreaking your device. Rather, you do have options. There are quite a few RPG classics you can play without jailbreaking. They're available legit in the App Store for around $3-16 US each. Those RPGs are:

• Adventures of Mana*
• Chrono Trigger
• Dragon Quest I
• Dragon Quest II
• Dragon Quest III
• Dragon Quest IV
• Dragon Quest V
• Dragon Quest VIII

• Final Fantasy 1
• Final Fantasy 2
• Final Fantasy 3*
• Final Fantasy 4*
• Final Fantasy 5
• Final Fantasy 6
• Final Fantasy 7

• Final Fantasy 9
• Final Fantasy Dimensions
• Final Fantasy Tactics
• Lunar Silver Star Story
• Phantasy Star II
• Secret of Mana
• Vay

*This game is a 3D remake of the original

I was told you can use Tweakbox to install video game emulators on iOS. Then use iExplorer to move ROMs/files around. If you install Tweakbox and over time iOS blocks it, search Google and YouTube for a workaround; people have posted fixes.

MacScene.net contains all the available video game emulators for Mac! It has a pretty active commnity, too. • You might also want to check Bannister.org because that guy alone made the majority of the available video game emulators for Mac. In other words, he's like the father of video game emulation on OSX. • For some reason, MacScene.net doesn't have a PS1 emulator posted. So to download one, go here: PCSX-Reloaded. • Also make sure to check out OpenEmu, a popular multi-system emulator with a great graphical front-end.

A multi-system emulator supporting Game Boy, Game Boy Advance, NES, and SNES. It works offline, has save states (right-click screen for access), and can load zipped ROMs. Emulation quality is pretty good with only a bit of scratchy audio. You need to manually enlarge the window to blow it up to a good size. Gamepads are not supported (they generally aren't on Chromebooks).
*If you have a newer Chromebook with access to the Play Store, you don't need to use this emulator. I found that RetroArch works the best on these new Chromebooks.

The easiest way to install video game emulators is to first install the Software Center (if you haven't already). There are plenty of videos on YouTube showing you how. Once installed, simply do a search for emulators to bring up the full list. Most of the emulators should work. Depending on your system and setup, some may not work. To install video game emulators manually without the Software Center requires a bit more than a beginner's understanding of Linux. YouTube is definitely your friend if you want to learn more about this. There are some really helpful videos out there, like this one: How to Create a Retro Gaming System with Ubuntu. Have you heard of the ultra affordable Raspberry PI? You can easily turn it into a RetroPie: How to setup a RetroPie. So for $35 US you'd have the ultimate video game emulation system!