I lost a lot of hours to import all my contacts from a Android phone to an iPhone. I tried to find the best solution on the internet, but, surprise, no method of all was good.
So, I tried to find a personal solution, and I remembered the Android Accounts. And, I navigate on iOS to find the Accounts sections that is available in settings. I make a login with my gmail account on my iPhone, and voila! All my contacts that was previous synchronized starts to appear in my iPhone Agenda.
This procedure took me only 1 minute to import all my contacts from my old Android Phone to my new iPhone.
Note: it is important to make a backup from your Android device to your Gmail. To do that, navigate to Settings -> Accounts -> Google -> Select your email address and press Sync. Wait the Sync to be finished and that’s it.
If you have some problems with this procedure please write me a message.