Friso Bostoen, PhD researcher at Consumer, Competition Market, KU Leuven (University of Leuven); Fellow of the Research Foundation - Flanders. In accordance with the ASCOLA Transparency and Disclosure Declaration, the author has nothing to disclose. For correspondence: <mailto:friso.bostoen@law.kuleuven.be>. This article is an adapted version of Friso Bostoen, ‘Epic v Apple (1): introducing antitrust’s latest Big Tech battle royale’ (CoRe Blog, 4 September 2020) <https://www.lexxion.eu/en/coreblogpost/epic-v-apple-1/> accessed 22 January 2021, with part of a follow-up blog post added as well: Friso Bostoen, ‘Epic v Apple (3): two perspectives on app stores’ 30% commission fee’ (CoRe Blog, 3 November 2020) <https://www.lexxion.eu/en/coreblogpost/epic-v-apple-3/> accessed 22 January 2021. This article and those blog posts draw on earlier work, in particular Friso Bostoen and Daniel Mândrescu, ‘Assessing abuse of dominance in the platform economy: a case study of app stores’ (2020) 16 European Competition Journal 431.