#1. Setting a PIN to your device and think it is good enough? NO.
When someone borrow your device and you cannot deny the request, you’ll end up giving them your phone with the password. Beside, in some cases, your girl friend, your wife, your parents... may even force you to spit the password out!
#2. Creating another account for others using the default multi user system? NO.
They may ask you: Why I have to use this account? Are you hiding something? Then you may also be forced to give them your main account as well.
#3. Installing a locker app which requires a password/pattern/fingerprints to open apps? NO.
The best protection is no one knows things are protected. As long as they know there's something you're hiding, they will try to bypass the security, or even force you to open the app.
With Ultimate App Protector, you can:
#1. Lock your device with just single account, but provide two passwords:
#2. One is for you, the owner: You can use your device without any restrictions.
#3. The other one is for others: They can use your device but they cannot access your protected apps.
#4. No one knows your private apps are being protected.
Ultimate App Protector also has the best abilities to protect itself from hackers:
#1. People also cannot disable the app from Device Administrators. It will only be disabled by you, who has the owner password.
#2. Even when the device's rebooted, the app will wake up automatically to continue to protect your privacy.
I was looking for an app that showed security (emails basically), this app looked promising. I only used it a short time because it still showed the app icon as available, so its not as secure as advertised. Additionally, this doesn't necessarily replace the locking screen so there is that additional process running. During the short time that I used it however, it blocked the app that I set to be blocked. I think it is a good idea, it just needs a little bit more work.