Photogenics works differently to Image FX.
You use the drawing tools to mark out any area you want to manipulate with an effect. Once marked out, selecting the effect will make that effect visible, but the original image is not permanently altered until you "fix" it. The advantage is that you can spray out the region you want effected with the free hand tool, and then just select a different effect, or alter the parameters of the effect, and the area selected is updated in real time, with the new effect. It is a layers system of sorts, and in many ways its faster than trying to set up layers and masks in photoshop.
Version 2 is easiest to come by these days, but can be a bit unstable. Never was a PPC version.
V4 and V5 had an interface update, but were quite unstable.
You really need a RTG card, but better still IMO is running it on Winuae.
Photogenics is still available to buy.
http://www.digitalriver.com/dr/v2/ec_MAIN.Entry10?SP=10023&PN=1&xid=39935&V1=371386&DSP=&CUR=840&PGRP=0&CACHE_ID=0It is unstable but not to the extent that it's unusable stability seems to improve with faster systems. Regular saving is a good idea. Crashes result in the UI freezing but it doesn't take the rest of the system down. It's my favourite graphics program for Amiga despite it's flaws.
edit
Photogenics' manual comes in electronic format and can be printed if needed.
Image and the manual can of course still be bought from Nova Design. Don't get confused with the UK based Nova Design.