Rocket boots are an item in Candy Box 2. They can be found in a chest in the third room of The desert fortress. Pressing 'j', with them equipped, will allow the player to fly.
Reaching the chest
Reaching the chest that contains the boots, high up in the top-right corner of the room, can be tricky. Make sure you have the Pogo stick and Desert bird feather. One way to obtain them is by making a 'staircase' of sorts with Tribe warriors with a Summoning Tribal Spear. Simply enter the room, and then teleport back to the beginning of the room every time you make a tribal warrior. Once you have a long enough row of tribe warriors, jump onto the row and spawn another. Repeating this enough will eventually get you to the chest. Below is what this should look something like: