How do you make those backups? Do you connect the phone to your MacBook and select 'Back up now' in the relevant Finder window? In that case the backups should only be under iOS files (within the 'manage storage' dialog). What is 'app storage' on your MacBook? Do you mean the 'applications' folder? Your iOS backups should not be in there, unless you're somehow manually copying stuff next to the regular backup process.