Created 14/08/2012- Zoiper 2.5 for iPhone, Libary Revision: 15333 SIP User Agent- Zoiper rev.15333
1) Open the app
2) Press 'Settings' icon, bottom left
3) Press 'Accounts', first option in list
4) Press '+', at the top right of the screen
5) Select 'SIP', at the top of the screen
6) Setup as per below -
Account Name - You can set this to whatever you like, its just a name for the account. I'd suggest Voipfone.
Username- If you're using a single phone, this is your account number. If your using Virtual PBX extension's, it should be your account number, an asterisk (*) and your extension number, in the format 3XXXXXXX*2XX
Password- If you used your account number, without an extension number for the username, this should be set to your master account password which Voipfone email to you when you sign up. If you're using extensions, each extension has its own password, which you can find by logging into your account and going here- https://www.voipfone.co.uk/account.php#view-pbx
Caller ID- This is your display name, which will appear on the screen of other Voip phone's when you call them. It can be set to anything you like, such as a name or business name.
Remaining settings can be left as default.
7) If you experience problems, trying adding the outbound proxy