Pro

1. Privacy: Allows users to read messages, photos, and stamps without sending a read receipt, maintaining privacy without alerting the sender.

2. Convenience: Users can check incoming communication at their own pace without feeling pressured to respond immediately.

3. Power Saving: Reduces battery drain by avoiding unnecessary app openings, as users can preview messages directly within the application.

Con

1. Privacy Concerns: Using "のぞきみ" may raise privacy issues, as it bypasses read notifications, potentially misleading senders about message status.

2. Trust Issues: The app can damage trust between users, as friends or contacts might feel deceived if they find out you've read messages without acknowledgment.

3. Security Risks: Installing and using third-party applications like "のぞきみ" can potentially expose your device to malware or unauthorized access, compromising personal data.