Has anyone made a program to listen to digital trunked police radio?

[M105]

I think if you want an idea of how much it will cost, you should look at some of the existing commercial SDR lines such as Flex. It is doubtful that someone is going to develop another version of something that sells for hundreds or thousands of dollars and give it away (unless they are pirating the software).

Nobody said "give it away". I don't know how big the market for consumer program like I am talking about would be but I think it would be much bigger than the commercial program you mention. With enough volume demand the price might be reasonable...maybe not. It is just a wish... Hey, folks pay $400-600 for a scanner.