2 way sync, 2 devices
 

So is it only possible to do a two way sync on each iOS device if I purchase 2 way sync addon on each?

26.00 a year for that???

I am sorry that I can't answer your question. I don't use the two-way-sync on more than one device, as I only have the iPhone, but I will say that it works well for me.

Perhaps someone that does, will chime in and answer your question. I know that there are several people using the two-way-sync as you describe.