What podcast app syncs with the iTunes MacOS podcasts?
I could have sworn that I just told you. You should post the OS and iOS versions of the Macs and iDevices involved.
I am answering from my viewpoint using Mac OS 10.11.6 and iOS 9.3.5, but with minor details this is basically the same as other OS and iOS version.
Assuming you already have podcasts in your Mac's iTunes then open iTunes and turn on the iDevice in question. Back in iTunes, click on the iDevice (sometimes this is a button ) and choose Podcasts from the Mac. This will then show you various options for selecting which ones to sync to your device.
When you want to
remove any Podcasts from the iDevice, just "un-click" the podcasts to take them off your iDevice and sync.
2. An option I prefer is to make a smart playlist for that (in my case) old time radio show with these parameters:
Match music for
all of the following rules:
Name contains (OTR)
Plays is less than 50
✓ Match only checked items
✓ Live updating
This will apply only music (where my radio shows go to) with the caveats of the text (OTR) is somewhere in each album title, and has been played from 0 to 49 (inclusive) times and the album and tracks are "checked". if any of these parameters isn't true. and because of the live updating, it will remove the track from the playlist, on both the Mac and the iDeveice automatically.
Good luck.
BG