I got a little more info about the "Memory Maker 1 Day" from the
MDE chat person. You need to already be in the park and get a PhotoPass photo taken by a PhotoPass photographer. Here's a link for the locations:
http://www.wdwinfo.com/wdwinfo/photopass.htm#locations
Link that photo to your MDE account (apparently you can do that with your Magic Band, with the Photographer).
Next, supposedly you need to get into the Photopass section of MDE app. (Not MemoryMaker, but PhotoPass). Click your photo that you just had taken. The next screen will supposedly give you the $59 1-day option, or the $14.95 option, or the $199 MemoryMaker option.
I haven't tried this myself. I've just read about. I've questioned the MDE chat people several times. Each time they give me partial info. Sometimes they give incorrect info, and later they correct themselves. I assume Disney wants you to purchase the $169 option ahead of time, and so they hide the $59 option until you're at the Park. If anyone can vouch that the $59 option still exists, that'd be great.