Textra can take up a ton of storage space on your phones HD when utilizing the setting to keep a certain number of SMS or MMS. This setting easily can inflate the storage.

By toggling the setting, it globally changes every conversion. Instead of trying to determine which conversations to set individually. There should be a screen which shows conversation sizes which would help a ton to iron out certain storage issues.

Love the app, I've supported and have been a premium user for years.