WhatsApp Messenger, Facebook Messenger and Skype are some free chat apps that work on both Nokia phones and iPhones. Other cross-platform chat apps include Kik and Viber.
WhatsApp Messenger is a chat service that works on iOS, Blackberry, Android, Windows and Symbian phones. Some primary chat features of WhatsApp include options to share photos, audios and videos, and group chats. Messaging on Whatsapp is free for users to send or receive messages as it uses the data plan for Web access.
Facebook Messenger requires users to install the application and works on Android, Nokia, iOS and Blackberry phones. Skype offers free Skype-to-Skype chat service with group chats, screen sharing and file sharing options. Along with messaging, it also provides worldwide voice and group video call service to mobiles and landlines and free calls between Skype users.
Kik and Viber share the same functions as WhatsApp and work on Nokia phones and iPhones. In addition, Kik includes open-source utilities that customize the mobile web platform. Viber does not require registration and provides free chatting and calling options to its users. These apps are often built into these smartphones and are also available for download from the Google Play Store, the Windows Phone Store and the iTunes App Store.