From what I remember from my Inc 2, HTC, being a social network friendly OEM, has a preloaded twitter and FB app. I don't remember exactly what the differences were, but I imagine they are just UI differences. The HTC twitter app will also most likely have better integration with photos and media. Try twitter for HTC and see if you like it better than the original twitter app, if not just use the app of your choice.
If you don't want to even see it on your app drawer, you can either disable the app if you're running ICS, or freeze it with Titanium backup if you are rooted.