Look, if you can't get someone to open your app more than 3 times, maybe it's because you are not making interesting things.
If you build something that is high-quality and that makes a difference in peoples' lives, they will flock to you, because there is so little of that. On the other hand, there is an overabundance of 99-cent and free-to-play software that has no real reason to exist other than to try and make the developers money. But this is the mindset that this article comes from (evidence: the author's first three pieces of advice are "cross-promote", "market well", and "internationalize", things that have nothing whatsoever to do with what is being made or how good it is.
These are not useful tactics, at least not in isolation, because they don't address the core problem: that a developer in this situation is a dime-a-dozen. The solution is to stop being a dime-a-dozen.
You don't need to differentiate your particular piece of software so much; work on differentiating yourself as a developer, in terms of the quality and interestingness of what you produce; be a thought-leader rather than a follower who mainly thinks about cross-promoting; and once you manage these things, you will automatically be doing okay. (And you are much more likely to be satisfied with your life, which is quite a nice side-benefit).
Of course, most people will not follow this advice, because it requires effort, introspection, course-changing, all that stuff. Most iOS developers will continue going as they are and continue suffering the consequences. Not pretty but that is just how it is!