It happened to me also. Slow internet connection is to blame for 0% progress of Store app updates.
What helped me was this: Disconnect internet connection and reconnect, then open Store and quickly go to downloads section. Close all downloads, and do not use those apps yet. Click check for updates and minimize Store, don't close. And final step...wait. Don't use internet browsers or other internet based services for at least one hour or two, I guess on slow connection Store downloads stop because of that. My connection is unlimited but now i had spent my data package so i get like 9.2 KB/s... waited for several hours and all apps are downloaded successfully. Good luck.