Google Translate says
Nun wird ein Tag
but I think it does not feel correct. Can we just say "Heute..."?
Are there any other ways to say this?
Now a days smartphones are very common.
Heutzutage is directly equivalent.
This is not 100% the same when used without a context like früher.
There is another closely linked possibility:
This would change the meaning though, since it implies that the situation might end and I doubt anybody can imply that.
Sorry to interrupt, but the English expression is not now a days, but nowadays, which directly translates to "heutzutage" or "heute" or "in der heutigen Zeit". Keep going.
As obviously this is requested in the comments, I'm going to pick up your example, which should be corrected to:
And could be translated as
I think it's heutzutage – alternatives could be just heute, gegenwärtig or zurzeit.