Osmium

Osmium is a fully offline, privacy-first TOTP authenticator for Android. Every secret is encrypted with a hardware-backed Android Keystore key before it touches disk. The app holds no network permission, creates no account, and sends no telemetry — codes are computed entirely on device.

Features TOTP and HOTP — SHA-1 / SHA-256 / SHA-512, 6 or 8 digits, periods from 1 to 600 seconds Google Authenticator migration — scan the "Transfer accounts" QR code from Google Authenticator and import all accounts in one step Encrypted backup — export to a password-protected, PIN-bound encrypted file; restore on any device Steam Guard — manual entry with the 26-character Steam alphabet (see warning below) Hidden codes mode — codes render as dots; copying still works, editing and sharing are locked until the mode is turned off Sort modes — random, alphabetical, add date, copy count Clock calibration — manual offset for devices whose clock drifts Security gate — optional verification on open (fingerprint / system password / app PIN), self-destruct PIN, screenshots blocked by default Ten languages — English, 简体中文, Español, 日本語, 한국어, Deutsch, Русский, Français, हिन्दी In-app manual — feature guide and important notes, bilingual Optional account name and issuer — blank names are auto-generated from the add date and order (e.g. 20260801); a blank issuer shows as Unknown