This app stores the content you entered (planning items, projects) into your iCloud private storage. The developer cannot access this information.
Only devices signed into your own Apple ID has access to these information. Apple Inc. manages the data within iCloud.
You need to refer to iCloud to understand how they manage these data.
II. Crash Logs
When the program crashes, a crash log will be sent to Apple Inc. to help us improve the application. The crash log will not contain your personal information.