I've been using AirPlayer with an iPod Touch and iOS9. It has worked quite well for me until the update to version 1.2.00 came from the Apple App store. Now, every track stutters when playback begins and eventually settles down after 5-10 seconds.
I confirmed the update was the culprit by using the previous version of AirPlayer that's on my iPhone (no automatic updates on my phone). The previous version still functions as it did before version 1.2.00.
I'm accessing FLAC files on a Linux server running minidlna. I don't use AirPlayer for video.
AirPlayer 1.2.00 is unusable for me.