[Cdesja5]

Works well but it does require a dropbox account on your devices to sync. I got it from the Market but if you install Aptoide which is an alternate market/installer you can find it by doing a search on Aptoide.
A word of warning about auto-sync... Don't do it! Set it to manual otherwise it will sync every time you turn on your devices and depending on how many books you have, it can be going for quite a while...