Error 80073cfb is an error encountered while updating/installing the apps. This is a software bug in the Widnows Phone OS as they have pushed an update, and as of now there is no official announcement from Microsoft about patching or fixing it.
However, I will keep you guys posted here as soon as their is an update on this, so bookmark this page.
A work around to get past this issue, that is reportedly working on a few devices which you may attempt by following the steps below.
Steps To Fix Error 80073cfb
Update 08:33 (UTC) 7/12/2015: Work Around #1
Go to the list of your apps that are pending for update, hold your finger on each app to pull menu and select “Cancel Update” or “Cancel Install”.
Once that is done, go to Windows Store and search for the apps you want to install and from there, select Update or Install.
Update 22:44 (UTC) 7/12/2015: Work Around #2
1. Cancel any pending downloads, and uninstall the apps causing the issue.
2. Go to the phone settings, and set the date / time to manually update.
3. Force your Microsoft account to update and sync.
4. Go back to the store and retry (download/update)
Update 01:22 (UTC) 7/14/2015: Work Around #3
1. Uninstall the App.
2. Attempt to reinstall.
3. Reboot holding power and volume button.
4. App will go to pending, and will install by itself.