How do you access Facebook and Twitter from stand-alone or webplayer?

There are some well-established plugins for accessing Facebook and Twitter from iOS games, but are there any that can do the same on other platforms?

Some plugins do appear in a search of the asset store, but at best I've found mixed reviews. We would mostly like to add a game-related post to the user's wall, rather than access all their personal information, and I want to avoid asking them to copy and paste a code to allow the app access if at all possible.

If anyone has used one of these plugins, or accessed Facebook without one, I would be grateful if you could share your experience of how you succeeded.