Normally, I tend not to comment (nor review applications–unless I deem it worthwhile) and unlike on account of the later, I admit that this app was downright brilliant! 

Pros–(There are plenty!)
· UI is organized and non-obtrusive; never lacking in customizable features and hand picked options.
· Lock screen controls are eye-pleasing and never lacking in overall appeal–from the unlocking motion to the colour palate, everything is well thought of and creates a welcomed experience. 
· The 'Home' screen is a highly welcomed feature. It's wonderful to see and for the system to automatically recognize where your new music can be found (and right from the get-go!) 

Cons–(We cannot have a biased view, and so it goes...)
· The only concern I have is with the 'built–in' tag editor; if there is a label I need to adjust, I find at times that I cannot always be certain that the SD-Card had fully scanned the changes. 
If there is someway–any shape or form–that could perhaps aid w/ that, any such advice (either formal or otherwise) would be greatly appreciated. 

But I say keep up the good work! I'm pretty excited for what is to be coming in the future.