I Would Say "Getting better day by day"
Because, in my point of view (maybe i'm mistaken) translating this sentence in a literal way, might sound a little bit strange for native speakers. I mean, saying: "Everyday better".
So, i'd tell you to say the first phrase:
"Getting better day by day"
Another option could be: "Can't Complain"
"Hey buddy, how is everything doing?"
"I Can't Complain bro" = "Eu não tenho do que reclamar"
I hope it helps!
Anyone who would like to share more, it's very welcome!