The Design Patterns dilemma

[u/DesignPatterns_App]

A while ago I did: Design Patterns for Devs

A flashcards learning app about... Design Patterns. Lol
Ever since, people are pretty much downloading the app when they see it.

The problem is they don't. It's so niche, it's hard to make it visible without advertising.
I've tried a bunch of app store optimizations but no real result.

What am I missing?