Twilio employee here. Check out the Quickstart docs on our website: it takes you step-by-step through the setup process for iOS: https://www.twilio.com/docs/quickstart/php/ios-client
Twilio will allow you to place phone calls and send SMS messages to numbers you have verified on your test account. Add your personal phone number to the Verified Called ID list here: https://www.twilio.com/user/account/phone-numbers/verified
I hope that helps!