Several 3rd party apps can't connect to internet?

Recently, several 3rd party apps on my mbp have been unable to connect to the internet. These include but are not limited to: Dropbox, Google Drive, Skype, Transmission, Evernote, Steam, Trillian, plex, several little useful apps such as mailtab for gmail. The Mac App Store is also having issues. I can, however, use Safari to browse with no issue at all. I'm connecting via wifi, no proxies or vpns or anything like that. Can anyone help me out here?