Zoiper Mobile (App)
From VoIP.ms Wiki
Configuration Setup
Download the Zoiper app from the Android Market or the Apple App Store
*Start the application -Click on Config (Android) or Settings (IOS) -Accounts -+ Add account
*Click on the + Add account sign on the top -Click on SIP or IAX depending the protocol you would like to use.
Fill in according to your account
Account Name: John Smith (your name)
Host: atlanta.voip.ms (one of our multiple servers)
Username: 100000 (your VoIP.ms username)
Password: ******** (account password)
Hit the Save Button
*You should be ready to make calls