It's not really a "free program" meant to be distributed separately and used w/any BT printer, it's the BB SW/drivers developed by PlanOn to be used in tandem w/their BT printer called the PrintStik.
Review by PCWorld mag: PC World - PrintStik Review
Planon download page: PLANon
Might still work as you'd like it to, but wanted to ensure the source/intent of the SW is clear...
BTW - The BB (at least as of OS 4.3) can print photos to a BT printer w/out any additional software...just select the image and then click the BB key and choose "Send using Bluetooth" and then select as target a BT printer you have paired w/the Blackberry. Pick will print out centered on 8 1/2 x 11 sheet (I've only tried it on a BT printer that only supported 8 1/2 x 11 paper).