Bathroom grooves

Ok, don't kick me out, I have a home audio newbie question...

I've started listening to my iPhone in the shower for the first time in my life, and it feels so lux.  

It's just that it's not very loud, and I have to prop it up precariously on the shower shelf.  

It go me thinking.  Are there some little blue tooth speakers for the bathroom?  Obviously, the bathroom isn't acoustically optimised :-) And I accept the limited space means limited audio quality.

Has anyone else here already done this?  How do you power them? 

Thanks, for any suggestions :-)