Yeah, so I'm a big kid and I've never grown up. One thing I've always wanted to do was be able to play Pokémon with me wherever I go but not have to carry around my Gameboy. This is more of a retro thing, but I've always liked the old school Pokémon (Red, Blue and Yellow) with the original 151 (Mew WAS an original) Pokémon and never a huge fan of all the extras they introduced over the years.
If you're like me, and own your old GB cartridges but they have started to fail (did you know that they have batteries in them, and they can go flat, I didn't till I lost my save games) then playing an emulated copy of your game is completely legal (provided you own a copy) and want to play all your old GB games on your iPhone or iPad (Android users there is something else for you and it's been around forever) without Jailbreaking your phone, now you can!
You can do so by using an awesome piece of software called GBA4iOS. The thing is, Apple did not like this piece of software (much like Neopets don't like Abrosia), so they banned it from the App Store. The developer managed to work out how his fanbase could download and install it using their Safari browser, without the need for Jailbreaking your iPhone / iPad.
The current version, which has been long anticipated, and months in development is the new version 2.0 which has only just been released (10 days ago now actually). This version introduced the ability to input Gameshark Codes and speed up the gameplay if you so wish.
Because you can't actually trade Pokémon to get those not available in your version (or final evolve some of your Pokémon), the gameshark codes do wonders for allowing you to capture those missing from your version of the game.
It's been years since I played Pokémon Yellow (I loved this version because it allowed me to replicate Ash's team by catching the same Pokémon he caught in the series including having my Pikachu follow me around) and now I can take it with me and play it wherever I go!
You can download GBA4iOS directly onto your phone / iPad from the Safari Browser from the official website: http://www.gba4iosapp.com
Note, because of the way it is written, his publication date was the 18th February, 2014 so in order to install the App / Roms for emulation, you need to set your iPhone time to BEFORE this date. Once the App is installed, you can then return your date to 'set automatically'. Every time you power off your device completely (ie battery completely dies or you've updated your phone and it required a restart) you will need to reset the time, open the App and then set your time back to automatic.
You do NOT need to keep the App open (meaning you can kill the task and fully close it so it doesn't continue to draw power) and you will be able to open it again. You only need to reset your time if your actual device powers off completely.
Enjoy!