Azdert Said:
"access to iaccounts: When trying to log into my iAccounts that holds all my passwords I get a message that says iAccounts needs to be updated. The developer of this app needs to update it to work with this version of iOS. Not sure how to fix."
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That is on the Developer:
It seems the developer has yet to do their part in compatibility with your iOS. So, contact them, using their contact information found on their app's site of the App Store.
So, what to Do:
Restore your iPhone from a Backup:
Have any backups of this iPhone prior to this occurrence? If so, then restore your iPhone from it. If not, then take this as a learning experience, knowing to always backup your device prior to making any major change to it(i.e. upgrading the iOS). Important: Back up you iPhone prior to performing this installation, should anything go wrong from here on out.