The same SimplePhotos version number is available for download, but you can now follow these instructions (included in the new INSTALL file) to enable caching of thumbnails, and add a description to a photo:

Enabling Caching of Thumbnails

1) Create a directory named ‘cache’ in the root of your webspace (right at the base level, not inside your SimplePhotos folder)

2) Chmod it to 777

Adding a Photo Description

To add a description to an image, follow this procedure.

If you have a photo named photo1.jpg in a folder, simply upload a text file with the following filename:

photo1.jpg.txt

Enter the description for that image inside the file. I appreciate this isn’t necessarily the best way of adding a description, but it does work.

Remember that if your photo had a filename ending in .JPG (capitals), your text file would have to end in .JPG.txt