Take AR FPS games a little too seriously with Xappr's gun attachment for smartphones
Best not take it out on public transport, though

Some people really like guns. These people will probably like Xappr: a new "virtual weapon" that makes AR games involving shooting things that little bit more engaging.
Unfortunately for gun aficionados, the Xappr and its little cousin the Micro-Xappr look nothing like a Heckler & Koch MP5 or a Remington ACR (who said games don't teach you anything?), and instead take the form of a sci-fi vacuum cleaner handle.
Your smartphone of choice from the Android, iOS, or Windows Phone platforms slots just above the handle, and acts as a laser sight on the virtual world.
Pointing northCreator of the device MetalCompass is due to release a multiplayer first-person shooter in the spring, called ATK, which utilises the peripheral.
There are also a number of Android and iOS AR games already on the market that support the device (full list on the official Xappr website).
The Xappr will be out in June, but is available to pre-order for $30 (no specific UK price just yet) if you're desperate to wrap your fingers around its plastic handle.