The following steps require jailbreak your device.
1. After you play the game for a while, save the highest score.
2. Open ifile and go to:
-> var/mobile/applications
-> doodle jump
-> library/preferences
-> com.yourcompany.DoodleJum p.plist.
3. Find the high score by looking "DoodleJumpHScore" eg. 10,000, then look for "DoodleJumpHScoreSent", eg 1.
4. Here is where you cheat on the system, in "DoodleJumpHash", edit the number between and change to whatever you want, eg 25,000.
5. Then find "DoodleJumpLocalHScores, edit the highest score to what you have just entered in "step 4".
Easter bunny
Enter Bunny as your name and your doodle will appear in a bunny outfit. You will need the latest update to make this work.