I use this one for most basic Porsche stuff:
https://www.ecstuning.com/b-schwaben-by ... ch01a~scf/
No subscription necessary. It reads all the modules and has some two-way functionality (reset service lights, etc). Also works great with generic OBD2 functionality on other cars when I don't want to get the giant Snap-On scanner out.
For anything more in-depth, I'd also recommend Durametric.