With all of these you can add the plugin from within the dashboard. Go to Plugins>Add New and search for the plugin by the name below.

Stats

Jetpack is big and bloaty but it gives you access to stats.

Add Jetpack Lite to get rid of everything above that you don’t need so use the two plugins together

 

Sales

WooCommerce will do more than you need it sets up all of the pages and is incredibly accomplished

Wp Ultra Simple PayPal cart is nowhere near as good but adds a PayPal option for the odd item.

I would go for Woo

Twitter Promotion

Not essential JM Twitter Cards is a neat way to add the Twitter Card headers needed to create Twitter cards  and add a much more appealing impact to tweets that relate back to a WordPress post. Worth getting your head round.

JM is a little French but OK. I’ve found that the image works well at 350×200.

 

The validation process is sometimes a little long winded but they are neat. This explains