I wanted to love this book so badly. And at several points in the story I thought now we're getting there but ... no. 
 I liked Jacob and I loved the idea of the pictures tying into the story BUT in the end, it is not for me. I'll list a couple of thoughts about why that is. 
 - the picture thing really never lives up to his potential. Most of the time it's like 'here, let me explain you a creepy thing that's happening and now look at a picture of the thing'. I had hoped that it would be more like ... finding old creepy photos as one does in the houses of dead relatives and, you know? things slowly clicking into place instead being explained in detail. 
 - the inevitable romance shoehorned in there which Jacob has some reservations about, or so he says before he proceeds to not give a single fuck about that. (I just can't get behind this particular romance trope) 
 - There was little plot and what was there, was predictable as hell. (view spoiler)[Golan was so shady, and the airport noises were so NOT subtle like - of course, he's the randomly appearing bird-spotting dude. Of course he abducts Ms. Peregrine, he is bird-spotting and she is the Bird. On the nose, much? And of course, the loop collapses, so many clues there. (hide spoiler)] I would have liked this book more, I think, if it was just a John Green-esque novel about Jacob coping with his grandpa's death by making up all the stories from the weird pictures he found. Because the moments when Jacob was thinking about his grandpa were my favourite moments that kept me invested enough to finish the book. 
 - I also had hopes that the peculiar children would be a little less ... normal. They just feel very one-dimensional and, granted, that's always a risk with a big cast but since they are peculiar it just stands out. 
 Anyways, those are just the thoughts I had to get out - and as a tl;dr: cool concept (underused), peculiar children (one-dimensional characters), plot (not very much or clever)