Hey!
I've been using this for a long time already and didn't even think about posting it until now!
You can fast forward or slow down any game using iGameGod! Fun for Minecraft timelapse and slow motions.
Download iGameGod on Cydia from https://iosgods.com/repo/
Open iGameGod from your home screen and enable which app you want to speed/slow
Open the app you enabled and you should see the iGameGod icon in-game
Long press the iGameGod icon and you will get the option to change to Speed Manager!
Now you can adjust your game speed easily using the Speed Manage UI!