1) Knowing your DevTools Is 100% Required
2) Offline Support is Essential
3) Client-Side Data Storage
Part of the way you can handle being offline is by making use of client-side data storage. Hybrid mobile apps can store data in SQLite databases, IndexedDB, WebStorage, and even the file system. Each of these methods has their own strengths and weaknesses as well as places where they make the most sense.
4) There's a Whole World Out There — Is Your App Ready?
Sometimes, it's easy to forget that our world is made of people who not only speak different languages, but also write dates and numbers in completely different ways. As a simple example, what day is this?
Is it April 8, 2017? Or is it August 4, 2017? That's a pretty important distinction. Consider numbers — here are three different ways of writing the exact same number:
1 000 000,99
While not quite as big a problem (I think folks who use periods for thousands separators would probably understand a number written using commas), it's still another point of possible confusion for your users.
And, of course, there's the issue of the app's user interface itself. Should it be an "Add to Cart" button or a … well, let's pretend I didn't forget my years of high school French and I could write the same text in French?
At the end of the day, preparing your app for an international audience could be crucially important for your success. As you can imagine, it adds a bit of work to your development, but it's also something that's better started in the beginning of your development cycle versus the end.
5) Making It Pretty
At the end of the day, it doesn't matter how cool your app is if it looks ugly. Making your app look nice on a mobile device is crucial and certainly can't be done at the last minute. For many hybrid mobile developers, this is where a good framework comes in, and for me, that's Ionic. Ionic helps my app look nice as well as providing common UX interfaces like "Pull to Refresh."
This is also the stage where I will remind you — you must test on real devices. If that means going out and buying an iPhone, then do so. While you can simulate most devices, nothing replaces actually using your app on a device and seeing how well it responds.
Yet another reason to test on real devices is to see how well your app performs. If clicking a button loads some data, what is that experience like on the mobile device? Do you need a "loader" widget of some sort to make it obvious that the app is doing something? Does your app transition nicely from page to page? DevTools can help out here as well!
7) And More…
Finally, other things you will want to check are accessibility and security. In both cases, there are plugins and plenty of support documentation to help with this.
As you can see, this is quite a list. Hopefully, it comes as no surprise that building a good app takes planning, energy, and a lot of hard work. Hybrid mobile development does help quite a bit, but developers new to this way of creating mobile apps should still be prepared to put in a lot of time to build a quality mobile app!