The iTunes App Store offers downloads of several applications for Apple iPhone and iPod touch for free, as listed below. At up to $10 off, each is at the lowest price we've seen. The deals:

• AgingSpine for iPhone, iPod touch, iPad: Spine anatomy, conditions, best practices, and more
• Tap-Translate for iPhone, iPod touch, and iPad: Translation tool
• Snap Ruler for iPhone, iPod touch, and iPad (pictured): Measurement tool
• Travel4Life for iPhone and iPod touch: Top-down shooter
• High Tower for iPhone, iPod touch, and iPad: Balancing game