It seems to be quite useful, especially when the interval shooting function is required. And almost all the Pentax DSLRs are supported! The *ist D and the Q are not mentioned, though.
http://www.wegroo.com/photoirmote/photoirmote/
Some of the screenshots can be found at their this sub-page. But before it works, an infrared (hardware) dongle, which is plugged into the phone jack of the phone, has to be built and clear instructions have been provided.
Btw, I might try it later with a Samsung Galaxy phone if I have the time and would report back later if tried.
Read Also:-
The Pentax (Electronic) Cable Switches
DIY Cable Switch/Release for Pentax K-m, K-x and K-r
A Pentax Q Time-lapse Example Video
A 45k-image 3-year Time-lapse Video with the K110D