The Twitter team recently announced that they’re turning off Basic Authentication (that we currently use) in favor of OAuth - http://dev.twitter.com/announcements - this means we’ll need to move people over to OAuth shortly.
We’ve automated the process for as many existing users as we can, but the addition process for new feeds has changed.
You need to make sure your Twitter account is listed under the 'Twitter Accounts' section of your account page, and if it's not just tap the 'Sign-in to Twitter' button to connect your Ultimate Notifier account to Twitter via OAuth.
For more information please drop us an email at support@ultimatenotifier.com