Useless/Mindless Raving

So I'm creating a ring tone for my own number on my husband's phone. He's got a Google phone and has downloaded an app that creates ring tones from music files. So I select a portion of a favorite song and voila: he has a ring tone that reflects me and one loud enough for him to hear me when I call him.
So...I'm excited about the possibilities on my own phone. I would no longer feel compelled to purchase ring tones. No longer be bound to our service provider's own ring tone store.
I downloaded a ring tone creator. I don't yet know how awesome or lame is may be. Why? It can only handle file formats I don't regularly use. Now, I know that my .m4a's on iTunes can be changed to compatible formats for the program (provided that there weren't purchased on iTunes and thus a protected format I have no interest in breaking to use for my own purpose. I'm not going to sell or spread around endless copies of purchased media. I want the song for ring tone (i.e. personal use only) purposes. That said, the mindless and/or useless raving is for this: I have all the songs I could want for various contacts ring tones, but I have to change the formats of said files to do so? Honestly it's not a big deal, this should be totally within my abilities to do. But why can't I just get software that can handle .m4a formats as is?