In an environment where your Mac needs to remain open without the complexities of creating addition users, how would you go about protecting your Mail app? Your Notes? Your Calendar from being tampered with? Or any app that you’d like to limit access too for that matter? Then you should be looking at Mac App Blocker (MAB).
There are a number of Apps that can achieve or might even have password protection built-in however my weapon of choice is MAB. I like the UI, ease of use and the 
customer support. Mac App Blocker is a very useful app that offers security when you can’t simply put in a login password. This is perfect for a shared work computer or a shared family computer.
Using MAB is pretty straight forward. You install, launch, set your password and
add whatever apps you’d like to secure to the blocked apps list. Every time you launch a blocked app MAB will prompt you to enter your password. Enter the password and you’re in. If you enter the wrong password, you’re not in and MAB keeps a log of the failed attempts. If you have a camera installed, MAB can also snap a picture at the time of the failed access attempt.
User Interface of MAB.
It’s easy to remove and add Apps. You can always change your password. Set it to launch at System Startup. There is a Lockdown mode which is very helpful at work when I need to run out to the bathroom, to a meeting, or to lunch.. I hit the Lockdown Mode Hotkey Combo and all my blocked apps are locked which pretty much means anyone who tries to access the Apps would be prompted for the password.
General Settings
Lockdown Mode is a godsend.
Stealth Mode keeps MAB discreet.
Registering and updating can all be conveniently accessed within the MAB App. You can set MAB to Hide, Lock or Quit a specific App after a specified amount of time during Inactivity.
Specify whether to Hide, Lock Quit or do nothing during inactivity.
As I mentioned earlier, MAB keeps a history log of failed attempts as well as usage stats:
Easy access to History and Usage.
An advanced feature which I have not used yet are Rules which you can apply per App. Just glancing through, it seems you can set a schedule to when an App runs and quits. So this is bordering Cron level type stuff which I’m sure would be useful in automating certain tasks associated with the selected App. Cool stuff.
Specify Rules to Schedule and much more!
Customer support is super friendly and responsive. I had a question which I emailed and they got back to me with solutions and will include fixes on future updates. It truly is an amazing App and will set you back $9.95 at the time of this writing which is a great deal for what it offers. I’ve been using it for more than a year now and it has and will continue to serve well. There is a 15 day free trial to get your feet wet first and evaluate if it’s somehting you could use.
Website: http://knewsense.com/macappblocker