I have published a program earlier this year that will convert Apple Monitor format text files into Apple 1 compatible AIF files. Only a checksum needs to be added at the end for Apple II compatibility. These AIF files can be used to load programs from an iPod through the cassette port, which is surprisingly simple way to move stuff into your Apple II. Not exactly what you are looking for, buy may be helpful to someone.
Not of their own manufacture, but you could connect any cassette recorder using the audio jacks.
Cassettes were not widely used with the Apple ][ after the first few years, because Apple was able to sell their software-driven disk drive and controller more cheaply than any other computer company at the time.
well, any audio player really... My $50 taiwanese made mp3 player could probably do it as long as I gave it an acceptably high bandwidth audio file to work with. It's not really a big ask for a digital device to be higher fidelity than your average old mono portable cassette deck from the late 70's.