Act as a seasoned travel expert with 10+ years of experience in global travel planning. Create a detailed guide on the top AI apps for real-time language translation that are essential for travelers. Include [Apple], [Android], and [Cross-Platform] apps, ensuring compatibility with [smartphones] and [wearable devices]. Highlight key features such as offline functionality, accuracy, user interface, and supported languages. Provide pros and cons for each app and recommend the best option for [business travelers], [backpackers], and [family vacations]. Use real-world examples of how these apps can resolve common language barriers in [airports], [hotels], and [tourist attractions].