How important is it to follow the iOS way of design when creating an app?

Question

I'm having an discussion with a customer and their 3rd party design company (let's call them X).

X is developing a native app for iOS and Android using Webview to show webpages delivered by me.

My "philosophy" is to create a design that will look the same on iOS and Android, save for the back button and other native stuff.

Things that differ are e.g. list items in Android has the right arrow while iOS don't. Tabs look very different in iOS than in Android.

Their argument is that the users are familiar with the iOS / Android environment and therefore we must stick to this.

My personal opinion is that this argument is b** :) I do not think that a iOS user will 'get lost or confused' when presented with an app that has a non-iOS look and feel.

Am I terribly wrong here and my customer and company X has some very valid points?

PS. I do understand the need for users to feel some familiarity to the environment they are using.

Answer 1

It's not so much about users 'getting lost or confused', more about whether users will trust your app. If your app looks and behaves totally differently to everything else on their OS then you run the risk of them not trusting it.

To quote this great article on SmashingMagazine:

1. Going against convention makes your application less intuitive. Over-styled controls look different and require users to re-learn how they work.
2. It’s a waste of time and money. The resources you have spent to make your app look different, but not necessarily better, could have been used much more effectively.

Here is a visual example they use. Which of these apps would instill the least amount of trust in users?

^{click to embiggen}