Social login from LoginPress is an add-on which provides a facility with your users to log in and Register via Facebook, Google and Twitter. This add-on will eliminate Spam and Bot registrations. This add-on will help your users to hassle-free registrations/logins on your site.
Easy Digital Downloads
EDD Custom Prices Addon 1.5.6
Allow customers to enter a pay-what-you-want price. This extension