Android and iOS apps

I am not sure if this is the right forum or whether the iPAD one is.
Sorry if I make a mistake, therefore.

I would like to know if somebody is succeding in synchronising the readers on the abovementioned platforms, not only in terms of books bought, but also in terms of annotations.
I am reading a book on the iPAD and, when I am on the road, on my Samsung Galaxy II. Until now if I annotate something on a device, it does not seem to affect the other. The same for the last page read.
Is it normal ?

THanks in advance