C‑EDD: Estimated Delivery Date

Can be a bit difficult to understand at first but once you get an understanding of how things work it's a pretty good app, I've compared it with others app this turned out to be the best option, I've tried like 3 or 4.
I've have contacted their customer support twice, I'm pleasantly surprised how quick they are to resolve any issues. oh and they don't waste your time, they just get it done.
I definitely recommend this app, go for the paid version, it's worth it.