It is impossible to be around your phone all the time. But it is possible to know is someone else tries to access your phone behind your back. Here are three apps which will take pictures of people who try to do this.
This is a basic app which functions in the background and takes a picture every time it detects wrong PIN or pattern is entered. The downside is that the app has ads and only stores the photos locally.
This app has a similar function but you get the additional benefit of receiving an email with the photos and locations for all unsuccessful attempts. This can be helpful in keeping a separate backup of all the evidence, just in case your phone gets broken or stolen before you can access the app.
In it’s free version, this is just like Crook Catcher. But if you unlock the pro version, you get the feature to detect SIM change and force power off/on. You also get the option to take multiple pictures and even record a 20-second sound clip using the mic. All this data will be then send to you via email. The real defining feature of this app however is that, even when offline, it can send an SMS containing the location of your device to a trusted friend of yours. It will also automatically retry to send you email updates once it comes into Wi-Fi range again.
With these apps, you can easily make sure that you phone is safe and secure, and that you know who exactly tries to mess with it.