LessPass vs Zero Password Manager (formerly ID Guard Offline)

Works everywhere, in any device that can run javascript.

If it's not stored, it can't be stolen.

On Android, you can check the app permission on Google Play Store or phone settings.
See here.
On iOS, you can check the app activity in the latest iOS 15 system.
See here.

The extension is a remote autofill framework without storing passwords or requiring sign-in. Its design can help minimizing the security risks caused by browser vulnerabilities.
After you scan the QR code on a desktop browser to confirm filling, your password will be encrypted on your mobile app first, then sent to the cloud server via a mobile browser, and finally arrive at the extension to be decrypted and filled in.
Check this to know more details.

The app protects your data with your phone's security chip, the same chip used by smartphone wallet to protect payment cards.
NFC Card in Android Pay.
iOS Apple Pay components.

You can back up all your data including passwords, OTP, attachments etc, with AES-256 and PBKDF2 encryption.
The app also allows you to send your backup password to your friends in encrypted form in case you forget it. Friends help save the encrypted backup password but cannot decrypt it, let alone access your database.

The app provides many account templates including tech giants like Google, crypto wallets like Binance, email accounts like CTemplar, game accounts like Steam, etc.
You can use these templates to save all your accounts' security information like recovery codes, security questions and answers, etc.

2 taps to autofill your username and password on mobile apps or browsers like Chrome, Edge, and Firefox.
Every time you use autofill, you must authenticate with your biometric or master password to unlock the app. So even if you temporarily lend your phone to someone else, you don't have to worry about them abusing autofill to sign in and spy on your accounts.

You can use it to save passwords, recovery codes, receipts, security questions and answers, etc.
There are also some helpful security tips about how to protect your Apple ID.

You can use the app to help enable 2FA for other platform accounts. The password, OTP, and recovery codes of an account can be saved together.
For example see this.

You can add attachments to save the photos of your ID cards, driver licenses, etc. in the app. Like other data, your notes and attachments are well protected with secure chip encryption and sandbox isolation.

As long as you enter the card number, ID Guard Offline app can automatically identify the card issuer, card organization and so on. It is easier than ever to store payment card information.

When you use autofill, the app can identify fake apps, display the requested information, automatically match the filling account, etc.
These security designs can prevent malicious apps or websites from defrauding your password with hidden password boxes, forged login interfaces, etc.

Every time you open the app, you are required to authenticate with biometric. If you have set a master password for extra protection, you can also unlock the app by entering the correct master password.

They shared a lot of blogs to show how to verify their security technologies like security chip encryption, true offline, autofill phishing detection, extension security design, etc.
Check out tech blogs.

With other password managers, if you forget your master password, your can't unlock your database forever. But this app is different. It allows you to send your master password to your friends in encrypted form in case you forget it. Friends help save the encrypted master password but cannot decrypt it, let alone access your database.

Its password generator allows you to fine control special characters to satisfy complex password requirements like containing certain symbols, the same characters cannot be sequential.
See here.

Neither the app nor the extension has trackers.
You need to be careful if you’re using a password manager with trackers. Because hackers may attack these trackers to steal your passwords.
See this

The app supports iOS and Android. The extension supports Chrome, Firefox, and Edge.
The extension only can be used with the help of the app because all your data is safely stored in the app on your phone with secure chip encryption and sandbox isolation, while the extension does not keep any data.
See this

After unlocking the app, you will see all the stored accounts' logos and names on the main interface. Tap a tag, like Tools, you can see the accounts with that tag.

Support importing CSV files exported from Chrome/Edge/Firefox/Safari/Myki or importing them with zip encryption mode.
You can also export your data from ID Guard Offline app in CSV or JSON format with password encryption.

Automatically record the changing histories of your accounts. This feature would be very helpful if you are using some platforms that ask for the last 3 passwords when changing a new one.

The app will automatically tag your stored accounts to help you manage them by categories. You can also add custom tags.

When you enter a password to save, the app will automatically detect its strength and let you know if it is a weak password.

To prevent someone from peeking at your passwords when you walk away temporarily, ID Guard Offline app will auto-lock if no interaction within 30 seconds.

So easy to use some features, like 1 tap to add account, 2 taps to autofill password.
The first time you open the app, it will ask you to use biometric authentication or set a master password as the protection method to protect your data. After finishing that step, you can go into the app’s main interface and start using it. It's straightforward to use without extra setup or redundant introductions.

• Access camera: Scan QR code to save or fill passwords.
• Use fingerprint hardware: Use fingerprint recognition to authenticate user (Cannot steal fingerprint data).
• Appear on top of other apps: An autofill bar will appear on top of the input box when autofill is enabled.
• Foreground service: Display the autofill bar when using accessibility service and let user know which app is displaying the floating bar.
• Google Play billing service: Unlock PRO features on Google Play. Google Play connects to the network to authorize user.
• Hide overlay windows: Hide overlay windows to prevent overlay attacks (Android 12+).
  No FULL NETWORK ACCESS. TRUE offline. Minimize the attack surface and can never leak any data or be attacked via the network.
  Check its permissions on Google Play

They pre-downloaded and packaged numerous platforms’ logos into the app. When you enter an app name to use its template to save a new account, the app will automatically show you the appropriate logo.
You can also select a picture from your system albums as your custom logo. And yet, if you are an Android user, you can pick logos from the installed apps on your phone.
See this

Neither require sign-up and login nor collect personal information. They have no idea who you are, let alone bother you with ad tracking or promotional emails.