Ask HN: AppLock - How secure is it?

I am the IT manager for a large retailer in India. We are thinking of purchasing hundreds of Android tablets for our workforce instead of lowend laptops, what we used to buy traditionally.

The primary use for these devices would be to capture data related to budgeting and Purchase orders and using our ERP tools.

As we do not want the staff to use the provided tablets for playing games and facebook and watching videos etc, we want to install AppLock (https://play.google.com/store/apps/details?id=com.domobile.applock) or something similar.

My Question is .. Is it possible to overcome the AppLock's Lock by fiddling with the filesystem of the device by connecting it to a PC/Mac - other than by factory resetting the device (which will erase our in-hour ERP apps anyway).