I have Pregnancy ++, Emma's diary, BOUNTY, Flo.
Flo I have it as I was using it to record my period. Now being pregnant it has a pregnancy mode and gives me some info there also.
Bounty and Emma's diary because they have some vouchers and discounts you can use.
Pregnancy ++ I bought with my second and now using for number 4.
I find all of them have some things I like, but none of them is super accurate with information.
Pregnancy ++ probably has the most things on it to read, but I find it's quite American in the facts.
Bounty has information from the NHS which I find good as I live in Uk.
Forgot to say I have the Maternity Notes for my online notes and has also lots of links and info from NHS( thou this app is used in my area and my hospital so don't know about other areas. I was sent a link and a code by midwife to be able to install it).