Problems with an Android app which crashes or won't start.
Sometimes a problem with game data means that the game can no longer complete it's startup sequence. This might happen because something has corrupted the data after it was saved, or (more rarely) because of a previously undiscovered bug.
The best way to fix this kind of problem is to clear out the game data;
On an Android device there is usually a settings app - it usually has a 'cog' style icon.
Each manufacturer tends to have their own settings app, so it may look a little different, but you should be able to find a section for Applications.
Look down the list of applications until you find the right game, and then tap to select it.
It will give you some options, but the best one to choose is Clear Data
For example (These pictures are on a Samsung Galaxy Tab 4, so it may look different on your device, but the same options should be there if you look around for them)
Select the application manager (sometimes called 'application list' or 'my applications')
Then Select the game (in this case Astraware Crosswords is used)
Then select the Clear Data option:
WARNING : This will clear everything saved for the app - any progress in games, statistics, achievements, high scores, and games in progress. If you have made any purchases within the game, you will be able to get these back by going to the in-app store and selecting Restore Purchases.
This is only intended as a last-resort for when the application won't start normally! You may wish to try a Force Stop first, as that sometimes will fix a problem without losing the data.