Also, does anyone else find it ironic that a habit tracking app has a monthly subscription? Feels darkly ironic looking at the IAP block towards the bottom.
This doesn't matter to most users (of a given target platform), and if you're charging money for an app—rather than making money with ads, or providing a service that needs maximum reach or user base, or relying on network effects to somehow make money as e.g. a messenger or social network might—then you only need/want iOS until you are seeing enough traction to be confident that the lower sales rate on Android will nonetheless be high enough to make it worth it.
Personally I don't care much if apps exclusive to iPhone, it's not going to stop me from buying an app. It's not like I'd be able to transfer the purchase to Android anyway.