Every developer on the planet has a strong opinion on whether you should adopt the native look of iOS 7 or if you should maintain an existing visual identity. Are you going to fit in? Or are you going to stand out? Both directions have a lot of advantages: marketing, biz, and design opportunities galore.
But don't buy into all the hype and dogma. I'm hearing these kinds of conversations every day: "You must fit into iOS 7. It's critical to look native". Or this: "No, you'll just be another cookie cutter in a sea of apps that look the same". These are reasonable arguments. The problem is:
Every app is different
Every app is different, and every app has different goals. As an app developer you need to stay focused on the real issue: making an app that works for your users. Do this and you'll be just fine.
As strange as it might seem, most normal people don't actually spend their time thinking about operating systems. Yep, they'll probably upgrade to iOS 7 automatically within the first week, but they won't be thinking about the OS like we do as developers. They just want your app to work. They want it to do what they need. They want it to be fun, or engaging, or simple, or useful.
So the decisions you make about your app should be based on your goals and principles. Not what everyone else is doing. Not what the market is doing. Dig deep into the philosophy behind the new OS, dig deep into the HIG. Learn about why they matter, and then make the best app you can for your users.
Make a deliberate choice
For some developers, this might mean moving with the crowd. You'll get some real benefits with the momentum around iOS 7. For others developers, it might mean a deliberate choice to move the other way: creating or maintaining your own identity. Both of these strategies are correct if done deliberately. Good design is about goals and constraints, and for every developer the right answer will be slightly different.
Here's an example
When I'm using a task-based app or a content-based app, I just want to get the task done, or to consume the content. I don't always need the developer's identity or ego to be expressed all the time. As a user, I might actually be quite happy to have an app that just looks and feels like it is part of the native OS. If it works, I'll be pretty happy.
On the other hand, there are so many apps for which my love of the app is based on the character of the app itself — pure expression from the developer & design team. Apps like these would lose all of their charm, all of their wonder, and all of their expression, if they were just delivered in a straight native style.
So. Be smart. Be deliberate. Build for your users. Build what they want.
How to express yourself in the landscape
If you decide you do want to fit into iOS 7 style, there are plenty of ways to do what is right for your users and stand out from the crowd. Everyone is caught up on how the OS looks right now, but there is so much more going on. The way iOS 7 looks is just a slice, a thin surface layer. Great designers and developers are digging deep into what is under the skin. They're already working on the heart and the blood and nerves inside.
So put your touches into your interaction design. Tell a better story. Spend time on the details. You can express yourself, and be different, and feel native all at the same time.
How This Is Going To Pan Out
In the next month we'll see many, many apps strictly adopt the new visual style of iOS 7. This is the first wave. Within a few months we'll see a massive attempt at differentiation as developers try to stand out from the pack. After that, we'll see the landscape settle down, and we'll see the apps that really work for their users start to dominate. They might fit into the native feel or they might not. It doesn't matter. They'll just be concentrating on what their users need, and I can't wait for that.