Instructions
Open Bejeweled Twist and double-click on the Cheat Engine icon on your desktop to start the tool. Click on the small computer icon under the "File" menu to start searching for the game.
Click on the "Window List" button, select the "Bejeweled Twist" entry and click on the "Open" button. Cheat Engine starts monitoring your game.
Write the number from the Bomb Gem's timer in Cheat Engine's "Value" box. Click on the "First Scan" button. You will see a lot of entries after the first scan. There is no way to know which one is the bomb timer.
Make a move in Bejeweled Twist. Enter the new Bomb Gem timer value in the Cheat Engine's "Value" box. Click on the "Next Scan" button. You will see fewer entries displayed.
Repeat the process until only one entry remains. If you have more than one Bomb Gem, the number of entries must be equal to the number of gems.
Select the entries from the list and place a check mark in the "Frozen" section at the bottom of the window to freeze the entries. Double-click on the "Value" section to change the values. Enter "99" and click on the "OK" button. The Gem Bomb timer will be frozen at "98" regardless of how many moves you make.