Here are the steps to register Fish Tycoon:
1)Install the trial version onto your device
2)Start the game
3)Click on the options button (image 1)
4)Click on the register button (image 2)
5)Enter your code (image 3)
6)Your game will be fully activated

I HAVE TRIED TO REGISTER WITH THE NUMBER I WAS GIVEN WHEN I PURCHASED THE GAME AND IT KEEPS TELLING ME UNLOCK CODE DOES NOT MATCH?????????????????/

Hello,
Please fill out our support form and give me all the info you can remember. Also, don't forget to give me the ID number that is displayed on the error page.
Thanks