My experience on changing the default LTR navigation direction on a popular eCommerce app in Iran
When you see the approach of Google and Apple for RTL languages, You see they mirror the wholeOS, if the back button is on top left in English, it's on the top right forArabic, also all the navigations, components and directions are flipped.
In Iranian applications ecosystem there's not a standard method. Most people are using EnglishOS (All of the iOS users but there is a segment of users that have Farsi Android), and Farsi apps have different approaches, some of them are completely flipped, some of them have LTR direction for navigation but the rest of the content are RTL.
When I was at Digikala, We decided to test each approach on each OS. We wanted to know for anIranian user who have an English OS, is it a good practice to keep the LTR navigation and just make the contents LTR or should we flip the navigation.
My hypothesis was that the users won't feel right when we change their global habit inside our app.
So we prepared two prototypes with different navigation directions. We test them with about 20selected users.
The results shown that there was a change in the way users navigate through our app, the most affected operation was at our check out process, sometimes users thought the back button is actually the "next" button.
Since there is no standard way for Iranian users to select Farsi for their OS languages (no way in iOS and the Android Farsi language is not available on every device) and it makes the situation for designers very bad, the final solution is really based on the context. As a product designer I normally choose the hybrid method for iOS users and an RTL direction for Android.