Can I use an app for multiple apple devices

On your iPad, open the App Store app and then perform a search for this app. IF the app is available for your iPad then it will show up in the search results. If it does not show up then you know that it is available only on the iPhone.

Axel F.

At one time apps ran on both the iPhone & iPad. But recently separate apps are generally required for the iPhone & iPad. Usually, if you purchase an app for one device the app developer will allow you to download the other version (if its exists) for the other device for free. But that is entirely up to the app developer. Check on the specific app in the App Store on both your devices. It should say what devices the app is compatible with.