1) Export contacts from the device into the SD card memory in 
vcf file format. Unfortunately, this would be extracted into a single 
vcf file, so MS Outlook is unable to import directly.
2) Convert this single file into a 
vcf file per contact:
   a) Import the file into Windows Contacts: 
%userprofile%
   b) Export the contacts into 
vcf
3) Drag and Drop all the 
vcf files into the Contacts\People folder for MS Outlook 2013.
4) Export all the contacts from MS Outlook into 
csv file which is a very versatile format and widely supported.
5) Import the just exported file into any mail service, in my case, I have used my 
gmail account at 
http://www.gmail.com
6) Configure iPhone to contacts to synchronize with the 
gmail account.
7) Done! All your contacts are now within your 
iPhone phone application\service contacts.
HTC Cha Cha - Android OS
Windows 8.1
MS Office 2013
iPhone iOS 8.1