PoolDose stores all of your data on your device only. There is no account, no sign-in, no cloud sync, no analytics, and no network communication of any kind. Your pool and spa readings, doses, and history never leave your iPhone unless you choose to export them yourself to a JSON file you control. Because PoolDose collects nothing and transmits nothing, there is no data for anyone to see, sell, or lose. This applies to every version and every territory.
This website (including the free dosing calculator) follows the same principle: it sets no cookies, uses no analytics or trackers, loads nothing from third parties, and sends nothing you type anywhere — every calculation runs locally in your browser.