Smartphone cameras are probably one of the wonders of the age. These high resolution video and still cameras have transformed the art of photography, and apps like Instagram have spawned a whole new ecosystem of sharing. But there are other uses for these cameras, some good and some not so valuable which have also come with the territory.

One example of the kind of app which can have multiple uses is Mobile Hidden Camera. On the one hand it’s a perfect way to use your camera discretely to keep watch on unsavory activities such as police excesses or human rights violations in wayward countries, and yet of course it can also be used for more underhand purposes as well. As with all tools, right?

This free software is impressive because it comes with a bunch of useful features. It supports both front and rear cameras, can disable shutter sounds on most cameras, features auto burst and continuous shooting at a touch, can auto split video to avoid file size limits and provides auto timer shut off for unattended video recording. But it’s when you want absolute stealth that it becomes a real ninja app.

Not only can it hide and encrypt all captured video and photo files, but it can also hide the whole app, and disguise it as a working notepad so even if your phone is seized it will not yield the secrets of your undercover documentary to unfriendly eyes. To start filming all you do is start typing in the notepad and enter your password along with the rest of the random words. The app can also make the phone look completely dead during shooting, with no backlit keys and a totally black screen.

Finally there’s an instant ‘wipe all’ feature buried in the app, so you can delete everything with one command. It probably won’t be good enough for deep forensic retrieval, but it should be safe enough to foil nosy Elbonian border guards. If you’re after the ultimate spy camera app, this is definitely it. A steal at the price.