Translation:I need you every day.
I understand that Yo isn't required, because it's implicit with "necesito", but where would Yo go, if I used it... Yo te... or te yo....
I wish that Duo would have an option to list the correct alternatives.
In this instance "Yo" isn't necessary, not only beacause it's implicated into necesito but adding the word "te" before it dictates the objective pronoun "you".
Like you said it isn't required, but if you were to add 'yo,' I think it would be: "Yo te necesito..."
Every day = cada dia