APA 7th edition
Cite and reference the individual or group that owns the rights to the app as the "author", and use the release date of the specific version of the mobile app you are referencing as the "publication date". The format for a reference entry is:
Author, A. (year). Name of app in italics and sentence case (Version number) [Mobile app]. Name of website. http://xxxx
For example:
AllTrails. (2019). AllTrails: Hike, bike, and run (10.4.2) [Mobile app]. App Store. https://apps.apple.com/ca/app/alltrails-hike-bike-run/id405075943
See pages 339 to 240 of the Publication Manual of the American Psychological Association for additional examples as well as information on citing a reference work app.