Apple II Games/Software Tapefiles at the web using MP3 or Wav tone

You can try ADTPro. But you will need to find Disk image files not Mp3 files. http://adtpro.sourceforge.net/ it lets you do image transfers through the audio ports on your host computer to the tape ports on the apple II. Setup information is avalible on there site.

I don't know of any "repository" of tape files, the way there is for Commodore users. Maybe it's because the Apple II community went so quickly and completely to disks.

If you come across any, you can of course send them directly. The CiderPress program can decode the digital audio and put it on a virtual disk image, too.

Of note - you don't want the lossy MP3, because it destroys part of what the Apple listens for in the compression process. Stick with WAV. This thread might be of interest, too:
http://www.applefritter.com/node/19961

I don't know of any "repository" of tape files