The Apple Wallet on the iPhone lets you sign up for and generate a virtual transit card (in Japan) without any third party app.
1. Create a virtual Suica in Wallet New for iOS 13: Create virtual Suica cards directly in Wallet in any iPhone language setting without using an app: Set iPhone Region to JapanOpen Wallet and tap the plus sign “+”Tap ContinueTap SuicaSelect a ¥ amount to put on your Suica cardFollow the steps to create a new transit card on your iPhoneReturn Region to desired preference