What's the best iOS app for messaging with fun stickers and syncing across devices?

Rakuten Viber Messenger is a robust messaging platform that combines playful expression with practical multi-device support. Its standout feature is the vast library of stickers, which users often highlight as more diverse and engaging than those in competing apps like WhatsApp or Line. For everyday use, such as family group chats or casual conversations with friends, these stickers add a layer of personality that text alone can't match. The app's desktop companion syncs messages and calls in real-time, allowing transitions from mobile to computer without losing conversation history. This is ideal for students juggling study sessions or professionals managing work communications across devices. Reviews indicate that many appreciate this as a straightforward alternative to Skype, with a clean interface that minimizes distractions. However, some advanced features, like exclusive sticker packs or enhanced call options, are reserved for the Viber Plus subscription, which might deter users seeking entirely free access. Despite this, the app maintains strong security with end-to-end encryption, addressing privacy concerns mentioned in feedback. Minor sync delays have been reported occasionally, but overall, it's a reliable choice for expressive, cross-platform messaging.