Tweetifier is a simple and beautifully designed app to keep track of your mentions and followers on Twitter.
It's not a full on Twitter client, but is designed for people who prefer to use the Twitter website and don't want to miss out on any new mentions.
⬩ Instantly alerts you when someone mentions you on Twitter
⬩ Shows a live count of how many new mentions you have in the menu bar
⬩ Floating desktop widgets display stats about your Twitter accounts and tracks how many followers you're losing or gaining
⬩ Allows you to quick reply to mentions
⬩ Allows you to archive tweets once you've read them
⬩ Allows you to monitor multiple Twitter accounts - all your mentions are displayed in a unified feed
⬩ Shows Growl or Notification Center notifications
⬩ Full Retina display support