Android
Using Gameshark with Gameboid
1. Ensure that you have a PC emulator for the same system as the game you play on your phone. For Gameboid, the VBAdvance is a good option.
2. Connect your phone to your PC via USB, put phone in Mass Storage mode.
3. COPY your ROM and it save file to your PC, in a folder of its own. Make sure that the ROM and save file are in the same folder together. Also, do NOT use a 'Save State' file, use an actual in-game save file.
4. Change the extension of the save file to '.sav'. Once again, this does NOT work for 'Save State' files.
5. Load ROM from phone on the PC. The game should load normally. Insert any Gameshark or other memory-editting codes you'd like, and then save the game again. Do not Save State!
-*-Remember, only one-shot cheats will work, such as 'Max Money' or 'Have 99 items'. Constant codes, like 'Invincibility' or 'Unlimited Items' will not function once you get back to your phone.-*-
6. Close the PC emulator, and change the extension of the save file back to '.sa1'. Delete the original save game file from your phone, and copy/paste the new file into the phone to replace it.
7. Remove phone from PC. Play game on phone; you will now have anything that you had at the time the game was saved on the PC.
**Tested using the Samsung Moment, the Gameboid application, and the VBAdvance emulator. Tested on two Pokemon games, and the DBZ Legacy of Goku series.**