Re: how to uninstall smart app lock without the password?
If the developer gives you a way to do it, I'd mark the app as being insecure. The idea of a passworded screen is that if you don't have the password, you can't get in. (If you forget the password, that's your fault - you should have a password app, with a data file in the cloud, that you can access from any device you own. So you use a laptop to look up the password for your phone screen. (That way you can have a single complex password to get to all the others. Use a 20 character mixed upper- and lower-case alpha, numeric and punctuation password and no one but the NSA is going to waste the effort it would take to break it. [That's military strength.])
That's also why you should never leave home with USB debugging enabled. Anyone who finds the phone can delete the pattern/PIN/password file and get into your phone. (If you need USB debugging on a lot when you're at home, use Tasker to automate enabling and disabling it. It can also automate using the locking screen when out and having the phone completely unlocked at home.)