Our source is correct. The same text is in that source.
If copied from somewhere else, it is also plagiarism.
The source that you provided is generic and ambiguous as no one is able to verify it unless they install that app.
Besides, owning the app does not make you the author of the text and gives you the right to monetise it.
Even if you provide the source of the text, it simply makes it a copypasta of text since you did not any significant, original writing in the article.