Generally the app Budget Blitz for Android do not need any service. But when you notice the app becomes slower service actions can help.
Shrinking database frees unused space, rebuilds the database file, repacking it into a minimal amount of disk space. This contributes to speed up the app. Shrinking database runs VACUUM command.
Shrinking does not affect to files that app contains except database.
Reindexing database is useful when you notice drastic drop in of the app performance. Reindexing runs REINDEX command.
Do not forget making backups, especially before service. Ensure you remember encryption password if you have. Otherwise restoring data could be impossible.