The plan on how to market the app should come before building the app, it isn't something that works best bolted on at the end. If the product is already built

The plan on how to market the app should come before building the app, it isn't something that works best bolted on at the end. If the product is already built, then the time is build out the user acquisition part, which is just as much of a challenge as building the product. One has to decide which UA channels to pursue, and basically A/B test towards success.