There were 3.2 billion smartphone users in 2019 and the number is continuously growing. Every year mobile devices come with new technology and so it becomes challenging for developers to develop an app which can seamlessly work with new technologies. One such technology is foldable mobile devices. Foldable smartphones are quite different from conventional smartphones, particularly with large screens, the app transition from cover screen to full-screen needs to be flawless. Developing an app for foldable devices is not easy. You need to deal with each detail, similar to whether the particular smartphone device has a single screen that unfolds or two different screens. While developing an application for foldable smartphones, you have to check for any hardware limitations. It is a challenge to design a perfect innovative UI that expands user productivity but then falls within the foldable smartphone application development cost.

Foldable app should work with multi-window mode and various form factors. Here we came with the some considerations that you need to consider while making an app for a foldable smartphone.

Factors To Consider When Developing Apps For Foldable Smartphones-

1. Make It Resizable-
When an app runs on a foldable smartphone, it should transition from an screen state to another automatically and seamlessly. App must always resume in the same location and state. For this, you have to develop a resizable app through dynamic resizing. The easiest way to do so is by using the code “resizeableActivity=true”. It offers the most extreme compatibility with whatever conditions and factors your application encounters. This helps the system in assuming that your app supports multi-window and resizable screens. The code helps an app being compatible with screen variations. It includes foldable phones, freeform windows and desktop screens.

2. Two State App Screens-
There are two ways that you can use some foldable phones- with folded screens and unfolded screens. It will affect the app functionality. So you need to consider which features you wish to reflect on which screen. For example- the unfolded screens of foldable phones that give you more space to work with. You can use it for an experience improvement. In this case, it is better to allow users to navigate with multiple fingers similarly instead of one. It is essential that you create an application that works ideally for both screens.

3. Screen Ratio Adjustments-
Foldable device app development revolves around screen and its various aspects. Mostly, foldable devices have short and bulky screens or long and thin screens. So while building a mobile app for foldable smartphones, you should ensure that screen concurs with varying screen sizes. You can implement minAspectRation and maxAspectRatio to check the screen’s compatibility with device.

4. Multi-Window Mode-
It is more annoying when one app pauses by opening another. And this what multi-window mode help in combatting. Foldable technology allows three or more apps to run at the same time. Also, the technology allows them to share content with each other. In case of Android 9 what used to happen was that only the application in focus used to be the resumed state and other activities were paused.

In Android 10, activities remained in resumed state even when in the multi-window mode. It is called as multi-resume. Add the following manifest meta-data to support this function within your app:

5. Supporting Multiple Screens Simultaneously-
Foldable phones need one screen support at a time, there is no guarantee that the future will be the same. Truth be told, many think soon; application developers should represent various screens at the same time. Handling with such a change will not be hard for application developers, despite the fact that it may now appear to be overwhelming. The reason behind this is the configuration required for multiple screens is like projected screens via Chrome OS. Android 10 and its latter versions support simultaneous activities on secondary and primary displays. Also, in case of secondary display, multiple screen and multi-resume functionality will apply.

While creating an app for foldable phone, you have to decide which of the two-screen you want as a primary screen. For the window resize, configuration change, and context update that should occur when an activity moves to a secondary display. You should specify same to your users.

Know more at- [https://solaceinfotech.com/blog/all-you-need-to-know-about-app-development-for-foldable-smartphones/]