Currently, no there isn't. (And we have ALL bemoaned the lack thereof.) The closest thing is the JACT Reading Greek program in three volumes, which is just traditional grammar with lots of easy reading stories. There's also Athenaze, but it's the same approach as JACT, except without the answers to the exercises (which makes it bad for independent learners).
If you're adventurous, you can try for the Italian edition of Athenaze
. Luis Miraglia translated Athenaze into Italian, and enamored as he was with LL, expanded all the readings to make them much, much longer, and had LLPSI-style pictures drawn to accompany the stories so you could acquire more of the vocabulary inductively. However, the grammar part and exercises are all in Italian. We were all hoping the next American edition of Athenaze would incorporate his changes, but it didn't.
Also, although it doesn't get mentioned much around here, about a hundred years ago W. H. Rouse produced an easy-reading Greek book with a continuous storyline, A Greek Boy at Home
, to accompany his First Greek Course textbook. Anne Mahoney has recently revised both books
, retitling the first to Rouse's Greek Boy