Was Tatian heretic?

[Havah]

Shlama all,

Was Tatian heretic?
I just flipped a few pages of The Panarion of Ephiphanius of Salamis in google books, and found that Ephiphanius accused him of being heretic.
Besides Diatessaron, what writings did Tatian leave to this world?
By the way, can I also have a list of writings of Justin Martyr?

Thanks