Note that there are two different things when we talk about “updating an app”: you can update the content of an app (adding a news, a discount code, an existing feature, the colors, etc), and you can update your application on the stores because you need to republish it.
In the first case, most of the time, you don’t need to update your app on the store and thus you don’t need to recompile it. Just change the content, or add the new feature, change the colors, and restart your app on your phone to see the changes.
But, if you change some other things that are native to the application like its startup images, its icon or its name, you will have to compile a new version of your app and republish it. In that case you will have to increase the version number before recompiling your app.
You will find more information about editing your app after its publication in this article HERE
