Twilio SMS Auth Integration

I need Twilio wired up to both the iOS and Android versions of my mobile app so users can verify their phone numbers and complete two-factor authentication with a one-time SMS code. My Twilio account is already active; what I am missing is the clean, production-ready implementation on each platform... (Budget: $30 - $250 USD, Jobs: Android, Android App Development, API Integration, iOS Development, iPhone, Mobile App Development, PHP, Twilio)