MightyText for Android. If you text a ton and are also at a computer the majority of the day, then this app is for you. Implements into Gmail as well.
Use it, only have two problems with it. The first is that I have a home screen app on my nexus that tells me when I have new messages, how many, and how they're from, and if I view the most recent of any of them in Mighty Text the notification won't go away unless I delete the conversation entirely. Not really their fualt I guess. The second is that their damn desktop app doesn't minimize go the taskbar.