Your data stays on your device and I have no access to it with the following exception:
If you have Apple iCloud enabled, your starting amount, transactions and categories also get stored in an encrypted way in your Apple iCloud account on Apple iCloud servers according to the Apple iCloud privacy policy.
If you delete the starting amount, transactions or categories while being connected to your Apple iCloud account, they will also get automatically deleted there.
If you still have any question about how your data is handled, look into the frequent questions inside the app or don't hesitate to send me an e-mailignore@yannikbloscheck.com.