'Every Day' is the story of A. A is an entity who wakes up in a different body every morning. The hosts are roughly the same age of A, as far as A can calculate, they have to be geographically close in some fashion and at midnight A is transported to a new host. A doesn't know what its deal is, just copes the best it can. A tries not to interfere too much with a host's life, that is, until A meets Rhiannon and is smitten.
There are many logical inconsistencies with the whole A thing, but I'm willing to suspend disbelief. I can't however, be OK with the icky stalker behavior A resorts to to stay in touch with Rhiannon. A does some serious damage to innocent kids. A big plot point is ruining one kids life because he retained some memory of his possession and freaks out about it, with only some belated sympathy from A. The plot touches on some other 'diverse' viewpoints, but so shallowly Levithan might not have even bothered.
The idea was refreshing enough and has potential, which nets it another star. The plot's resolution begged for sequels, which it has received. I'm not going to bother.