I discovered Airport Express has been discontinued. I have one connected to my preamp via optical S/PDIF, which permits me listen to iTunes on HT wirelessly delivered from my laptop, iPad, and iPhone. I thought today about buying another one for this scenario: iPhone wireless to Airport Express and Airport Express RCA out to 1/4 inch plug connected to powered JBL 305's. Seems like a nice way to enjoy iTunes with some portability around the house. At any rate, now it appears I need something else that does what Airport Express does however I do not know what's out there.
It's discontinued, not unusable. AppleTV and most AV receivers, as well as Yamaha MusicCast, Denon's HEOS and some other streaming devices can work with AirPlay. Newer models use AirPlay2, which allows connecting to more than one device from the source, so consider that.
Apple announced that they were discontinuing development and support for their network hardware last year- it was overdue from the networking side, but for AirPlay users, not.
If you want to use a wired connection, look for a cable than connects to the charging port on the phone, rather than using the headphone jack- it sounds better and you get more output.