noun
messenger app; messaging application
Refers to software for instant messaging, such as LINE, WhatsApp, or Facebook Messenger.
友達とメッセンジャーアプリでやりとりしている。
I'm chatting with a friend on a messenger app.
Variant with interpunct; less common in everyday writing.
Similar meaning, but メッセンジャーアプリ emphasizes the 'messenger' aspect (often real-time chat), while メッセージアプリ is a broader term for any messaging app.
Wasei-eigo (Japanese-made English) from 'messenger' + 'app'.