I don't know of any free ones, but this has a
demo you can try.
You might already know, but just in case you don't, you can print one from iTunes, although the options are limited.
Printing a Jewel-Case Insert
Step 1 Select a playlist in the Source area, and then choose Print from the File menu.
Step 2 Click on the CD Jewel Case Insert option (see “Instant Art”). You’ll also see options here for printing several types of song and album lists.
Next, choose an album design from the Theme pull-down menu. If your playlist contains songs from multiple albums, you can use the Mosaic themes to produce a collage of album art. Want to use just one album’s art for the cover? Select the playlist song containing that art before choosing Print.
Step 3 Click on Page Setup and adjust the settings for your printer as needed. Click on OK to return to the Print dialog box, and then click on Print.
Step 4 Once it’s printed, trim the case insert using the crop marks at the edge of the image as a guide.
--from "Macworld"