Is there anything for steam?

No its for android phone, tablet etc.

Edit: Yes you can

Unlock on Steam

Pay $1 or more and you’ll
get a Steam key in addition to
DRM-free direct downloads

All of them

Reading helps:

"Unlock on Steam

Pay $1 or more and you’ll
get a Steam key in addition to
DRM-free direct downloads"

All of those games activate on steam, yes, if thats whats you're asking. If you pay more than a buck you'll get steam keys.

All of them!