For instance, if you use Expo, which is a fantastic service which I HIGHLY recommend you look into, you push your code to Expo’s servers and can send your friends or your employer a link to beta test. If they have the Expo app installed on their mobile devices, once they click on the link, the app will load from Expo’s servers and run on their devices.
Eventually, you’ll want to build a standalone app file, which you can do with one line in terminal. Once the app is on the store, and your customers are using the app, if you want to make an update, all you have to do is push your new code to Expo’s servers. The next time the customers load your app, they will be running the new code (since it’s run from Expo’s servers).
Similarly, you can use Microsoft Code Push. Never before has it been so easy to update your app. There’s no need for you to keep having to be approved by apple for each incremental update, and there is no need for your customers to download the new updates from the app store. It really is THAT simple :)