As there are many privacy issues with our handsets so i have recently downloaded application lock on my mobile but i have many times noticed that when i close any of the application which i have locked and open it after a while it doesn't asks me for the required code. So i would like to know that is there a problem with application lock app or with my handset  ?
Sometime mobile App Lock allows to pass without typing password
I guess the one you should be checking is the information about the app lock you installed. Maybe the program is configured to not ask for a password or a security code if the elapse time has not yet passed. It will only ask for the required security code after the time has expired.
Before installing any app lock application on your phone, make sure to read the application’s information on how it works, its features, and how to properly use it. You should also check if the app offers different account types and you are using the free type which may be less secure compared to the other 2.
If this is the case, upgrading your account type should fix the problem. If you have a problem with the app lock software you installed on your phone, try using AppLock from DoMobile Lab.
It offers 3 account types to choose from: premium, ad, and basic. The premium type offers premium features, no ad, and it is paid. For the ad type, it is free, premium features available, but with ads. For the basic type, it is free, no ads, and doesn’t include premium features.