iPhone 7 Plus with iOS 10.3.1
I had three apps that were experiencing issues with updating.
• I went into the App Store to see if any apps needed updating. Several were listed. I touched "Update All" and all of the listed apps appeared to update.
• Upon returning to my Home Screen, I noted blue dots next to the apps that had updated. I opened each app and the blue dots went away.
• I returned to the App Store later and found that three of the previously updated apps required updating. I was not sure if this was an additional, more recent update. I touched "Update All" again, and all three apps appeared to update again.
• Once again, I returned to the Home Screen and found blue dots next to the applications noting their updated status.
• Curious as to what was occurring, I immediately returned to the App Store. The same three apps needed updating. By checking the updated dates, I determined these were not new updates. They were the same update I had already installed.
• I uninstalled all three apps. Restarted my iPhone. Then reinstalled the apps. The problem described above persisted despite the apps being reinstalled.
• I went to the App Store and cleared the cache by tapping the bottom navigation bar 10 times. The screen flashed white to indicate the cache clearing. I returned to the Updates tab and determined the problem above persisted.
• I did a two-button hard restart on the phone. On the iPhone 7 Plus, this is done by holding down the power button and the volume-down button until the Apple Logo appears, then release. Upon returning to the App Store, I determined the problem persisted. All three apps were still listed as requiring updates.
• I restored the phone from a backup on my computer. I went through many of the steps listed above, including clearing the App Store cache, after the restore. The problem persisted.