yaMPC 4+

All networking operations appear to happen on the UI thread, which causes the app to freeze if it is in the middle of something. No indication that the app hasn't crashed. It often stays this way until some timeout has reached, which can be as long as 30 seconds (!!!). It will sometimes give you cryptic dialogs like "when there is a check mark, press <Queue" which makes me feel like I'm answering a riddle to cross a bridge or something. The app does at least function, though. But there aren't any better MPD clients on the app store.

Thanks for the feedback. I agree that the message "when there is a check mark, ..." is confusing. We will fix it in the next version.　The message only appears the first time you make an MPD connection. Therefore, we recommend that you read the tutorial when you start using yaMPC.
The "Developer Web Site" link of this App Store page, then English-yaMPC-Tutorial, or
visit “openaudiolab.com/yampc/tutorial/”

yaMPC blocks its UI until the MPD connection is complete (or timeout). However, once a stable connection is established between yaMPC and MPD, I do not think you have to wait for a timeout. If you still have an issue, please contact us and we will be happy to help.
The "App Support" link of this App Store page, or
visit “openaudiolab.com/yampc/support/”
and find our email address in the "Ask a question to" section.

Works as advertised. User needs to have basic understanding of how MPD works. Thank you to the developer for making this app!

Many thanks for your review comment, I appreciate. I am sure your are familiar with MPD. However, for those who are not familiar with MPD, we will add more information, including fundamental tutorials, to the yaMPC Web pages. For now, we hope that every user will visit our web site (openaudiolab.com/yampc) and check Online Manual, Support information (Known Problems and Technical FAQ) and Cover-art settings.