Complex sentence: Similarly, over-the-top messaging is third parties providing instant messaging services as an alternative to text messaging services provided by a mobile network operator, particularly WhatsApp, which is narrowly focused to replace text messaging on Internet connected smartphones.
Split into simpler sentences: Similarly, over-the-top messaging is third parties providing instant messaging services as an alternative to text messaging services provided by a mobile network operator. Particularly WhatsApp narrowly focused to replace text messaging on Internet connected smartphones.