As for its security design, here are some examples:
1. The data stored in the app is protected by the security chip, the same chip used by smartphone wallet to protect payment cards. Even if the encrypted data is stolen by means of app clone or phone backup, or the set master password is leaked, your passwords will not be disclosed. Check this out https://www.bluespace.tech/blog/evolution-of-password-manage...
2. The app doesn't have Internet permission, so your data can never be uploaded to the cloud secretly. Your data is totally under your control. This is also verifiable https://www.bluespace.tech/blog/offline/
3. Its autofill can help you detect phishing attack to prevent malicious app from stealing your passwords. It can identify overlay attacks, show what to be filled, etc. Take this video for example https://www.bluespace.tech/blog/advanced-phishing-detection/
4. The design of its desktop browser extension is really nice. The extension accesses the Internet but doesn't store data, and the app stores data but doesn't access the Internet. The two attack surfaces of storage and network are separate. It means browser vulnerabilities can't affect the security of other passwords stored in the app. Check this out https://www.bluespace.tech/blog/extension-security-design/
Thanks.