For Android devices:
- Go to device settings > Applications
- Select Dream Blast in the application list
- Find the Clear Cache button, tap it, and reopen the game
For iOS devices:
There is no specific option to clear a single app's cache. The best method is to uninstall and reinstall the game.
NOTE: ONLY reinstall if your progress is saved via Facebook, Google Play, or Sign with Apple. This way, you can restore your progress after reinstalling.