Will there be UnearthedArcana avaible here later on ? maybe in it's own section.
And will Elemental evil spells and from other books be included in spell list later?

All the 5th edition stuff will be part of this application. They don't have declared the price yet.

The unearthed arcana material I guess that needs to be published first.

I am hoping that there will be Unearthed Arcana support in phase 3, with "Homebrew Integration".

In fact, I have the feeling I saw that mentioned somewhere, but I can't find it.