Let’s start with defining exactly what app localization and app internationalization are. According to this article, internationalization entails the entire, overall process of tailoring an app to a foreign market. Localization is the specific item-by-item translation and customization of each app asset (e.g.: text, graphics, etc.). This largely involves language translation but also includes the conversion of units of measure and assessment of culturally appropriate images.
If you are limiting your app to only one language, you’re missing out. Across Canada, we have two official languages English and French, so even including a French version of your app could drive your downloads up and keep the popularity going. You can even consider breaking into the international markets, considering over 50% of the countries that appear in the top 10 list for downloading apps are non-English speaking (the According to a survey by Common Sense Advisory).