Like saying the words "bee pee minus" (bē pē mīnŭs). The name comes from the common musician acronym "BPM" (standing for "Beats Per Minute", a common measure of tempo) combined with the word "minus" to indicate you can slow down the tempo.
Yes! The Windows version of BPMinus is free and will remain free.
Not at the moment. We won't rule out there ever being a Mac version, but we're not currently working on one. We love Apple products, and BPMinus was actually programmed on Mac hardware. But, it was built using a lot of Windows technologies (like the vector-based UI) that would make it difficult just to port over to the Mac OS X platform. There are also some decent BPMinus alternatives on the Mac OS X, so we didn't feel as compelled to make a Mac version.
This is most likely because the file is in a format that BPMinus cannot recognize without a plugin. For licensing reasons, we can't include compatibility with every file format on every operating system. But fret not! BPMinus supports many Add-Ons for reading file types. If you've tried the Add-Ons, don't know which Add-On to use, or are otherwise still having problems, please feel free to contact me and we'll see if we can sort it out!