My apps do not collect any information to identify who users are. Several of my apps collect anonymous usage information such as how often a given feature is used or whether an app crashed to aid in improving most-used app features and for debugging, respectively.
All of my apps store your data e.g. photos and spreadsheets on your device alone until you send your data e.g. via email. Nothing is sent to my server except usage statistics.
If you have enabled Apple's iCloud you're likely sending your data to Apple's servers. That would happen automatically; my apps ignore iCloud.
No anonymous data that is collected is given to any third party by me except out of necessity to my hosting provider. I do not sell any usage information. It is conceivable that my hosting provider may be obligated by law without my knowledge or consent to provide it to governments.