Clearing the cache of an app clears some memory space from your phone but it also removes all saved data on that app. Be sure to know what you are doing before doing this.
Follow these steps to do a clear cache of an app on your android device:
1. Go to Settings > "Application Manager" or "Apps" or "Applications". The name is different depending on the device.
2. Tap an app you want to clear the cache.
3. On the items listed, you will find the "Clear Cache" button. Tap it to clear the Cache for that App.