How do I cite an article I found using an iPhone app?

It is irrelevant whether you read it on your iPhone, IPad, Android, Blackberry, MAC, laptop or in the library. Creating references is not about documenting “how” you located the information but providing the reader a direct path to the “original” source of the material.
Remember – the “iPhone app” is not the source of the article – the “journal” is your source. Cite it as you would any journal article.
The basics of a reference list entry for a thesis or dissertation:
Example:
Mosek, E. (2017). Team flow: The missing piece in performance [Doctoral dissertation, Victoria University]. Victoria University Research Repository. http://vuir.vu.edu.au/35038/

(Source: https://libraryguides.vu.edu.au/apa-referencing/7Theses,2024)
General Rule:
Author, A. A. (year). Title of doctoral dissertation or master’s thesis (Publication No. #) [Doctoral dissertation or master’s thesis, Name of Institution Awarding the Degree]. Name of Database.
Example:
Cash, S. S. (2009). Emotional intelligence, a necessary component of educational leadership programs,as perceived by professors of educational leadership. (Publication No. 3429815) [Doctoral dissertation, Cornell University]. ProQuest Dissertations and Theses Global.
General Rule:
Author, A. A. (year). Title of doctoral dissertation or master’s thesis [Doctoral dissertation or master’s thesis, Name of Institution]. Name of Website. URL
Example:
Buckman, A. (1997). MOOSE Crossing: Construction, community, and learning in a networked virtual world for kids [Doctoral dissertation, Massachusetts Institute of Technology]. DSpace@MIT. https://dspace.mit.edu/handle/1721.1/33821
General Rule:
Author, A. A. (year). Title of doctoral dissertation or master’s thesis [Unpublished doctoral dissertation or master’s thesis]. Name of Institution.
Example:
Stephen, R.P. (2022). A study of instructional objectives and methods for interpersonal communication. [Unpublished master’s thesis]. Universiti Utara Malaysia.