I've been thinking about this for awhile and another thread reminded me to bring it up. Considering the personal information one can maintain on one's phone, it amazes me that so few developers include an option to require a password to access individual applications.
I realize, of course, that one can implement a lock pattern on the phone itself, but frankly I find that to be a major PITA. In fact, I don't even like to have to use the lock screen when I wake up my phone. (That's an easily solved problem, of course.) And I also realize that I can use third party applications to erase the data from my phone in the event it's lost or stolen. But, again, that's a drastic solution that makes sense only in an extreme case.
What I would like to do is prevent access to my email accounts, the information about my auto insurance policies, and other personal data maintained within applications. I can do this with particular note files by encrypting them. (NoteEverything) And if I maintain credit card information on my phone most third party apps provide for password security. But I cannot block access to my email, my calendar, information about my automobile, etc selectively. If I allow someone to examine my phone all that information is readily accessible.
So I suppose this is a two-fold request. Ideally, I would like to have an application that allows me to interpose a password security screen between the activation of another application on my home screen (or the task drawer) and the app itself. With such an app I could choose whether to block access to any application by someone who doesn't know a password.
Failing that, I would ask developers of individual applications to consider providing this feature if their app stores and/or accesses potentially sensitive data.