iPhone iOS7 apps stay open in App Store after install How does one remove a downloaded and installed app from the App Store Purchases page? 

Deleting and re-installing does not seem to work. There is a very long discussion stream on the Apple forums about this particularly minor seeming but very annoying phenomena. Moreover, there doesn't seem to be any applicable, actionable solutions except to wait several days for the apps to go away. The "OPEN" just sits there.
To remove from my updates page I merely went to Settings, under Date and Time and toggled off Set automatically and changed the date and time a few weeks ahead. You can change the settings back after checking your app page to see that they're gone. It works!