"App Store standards" don't really work for valuable niche software. They can work for games that end up selling 10 million copies, but there's a reason why pro

"App Store standards" don't really work for valuable niche software. They can work for games that end up selling 10 million copies, but there's a reason why professional software with few users is usually priced between $500 and $100 000. $5 is worth 3 minutes of developer time at common hourly contracting prices. If a developer receives and reads an email from a customer, they will probably end up with no profit. If they respond to it, let alone are adding new custom features, they are certainly losing money compared to working for someone else.