Correct me if I'm wrong but I know Blockfolio came before the other three apps. If it's the first, you can't say that there's nothing unique there. The other apps probably used the features of Blockfolio as basis and added some of their own.
I currently use Blockfolio and Delta but every trader has their own preference. I am not familiar with the other two and I might check it out too.
I mean it doesn't really matter for the users who was first? What matters is how delivers the most value to its users.
Not like facebook was the first social network, but they did what others had done before and more!