From the app
Open HiCash and go to Settings → Backup to your Google Drive → Delete my account. Your HiCash account and the backups HiCash saved in your Google Drive are deleted immediately.
Without the app
Email hicash.support@gmail.com from your Google account address, with the subject "Delete my HiCash account". We delete it within 30 days and confirm by email.
You can also delete the backups HiCash saved in your Drive yourself: on drive.google.com, open Settings → Manage apps → HiCash → Options → "Delete hidden app data".
What is deleted, and what was never kept
Your account record is deleted: your email, your name and your user identifier. We keep none of it afterwards.
Your financial data was never on our systems: it lives on your phone and, if you turned on automatic backup, in HiCash's private folder in your own Google Drive. Deleting the account does not touch the data on your phone.