iOS Productivity App UX Testing

I'm looking for detail-oriented person with access to testers to evaluate a free iOS security app. The app is live on the Apple App Store. I need thorough, honest testing to identify bugs, usability issues, and false positives/negatives before I expand it... (Budget: $30 - $250 USD, Jobs: App Usability Analysis, iOS Development, iPhone, Mobile App Development, Mobile App Testing, Testing / QA, Usability Testing, User Experience Research)