Not following exchange rates closely can lose you a lot of money.
As most of the readers of this article will know, Apple only permits developers to sell apps at certain price points that are called price tiers. This great article summarizes how Apple runs price tiers. Apple also gives developers the ability to charge users in their local currencies (i.e. the currency of their AppStore country) for most countries. In certain cases when a country’s currency depreciates too much, Apple can step in and update its local pricing tiers but this remains an exception rather than the rule.
This is why currency fluctuations can result in lost income in some countries in USD terms. This lost income often goes unnoticed since it is hard to spot and you are not warned against its effects: our algorithms spot whenever this happens and warn you.You can then reset the pricing accordingly: however, thread carefully because you might not want to increase prices in the said local currency if the users are losing too much purchasing power and be inclined to churn if prices are too inflated.