Can apps use different Twitter accounts on iOS? Now that iOS has Twitter integration, and many apps use these credentials rather than asking you for the Username and Password, I was wondering if there was any way to tell each app which account to use.

For example, in Settings > Twitter, you can sign on to multiple accounts. Now let's say I use 2 apps that both have Twitter integration. Is there any way App A could use one account on Twitter and App B could use my other account?

Furthermore, I notice that at the bottom of the Twitter settings page, it shows a list of apps that have access to Twitter. Is there any way to allow each application access to only a specific Twitter account?

I noticed that the Twitter app itself has a
Developers access your Twitter accounts through the Accounts framework.

When an app requests access to your accounts, it uses the requestAccessToAccountsWithType:withCompletionHandler: method. (The only supported account type is currently ACAccountTypeIdentifierTwitter.) This grants access to all accounts of that type.

Therefore, unfortunately, apps can't request access to only a single account — you have to give access to all of your Twitter accounts.