I don't quite understand your point. Is Drip non-pink to include trans men? That sounds really far fetched to me. And your friend found it ugly because it's not pink? Design is obviously subjectivity and perhaps your friend prefers the color pink, but has any of this actually anything to do with trans people and inclusiveness?

What's your reasoning for the conclusion of the app looking the way it does due to this and not due to the developer just subjectively preferring this design?

In the app description: "Not another cute, pink app. drip. is designed with gender inclusivity in mind"

So it's a perfectly conscious choice, and that's exactly what turns off some women who might prefer a cute, pink app. I have nothing against inclusivity, quite the opposite, but in this case they could offer two themes rather than imposing an app that isn't "cute". Even as a man, you can prefer cute things.