Duplicate apps on all devices

First you can delete the apps that you don't want on your iPad but that doesn't actually solve the greater issue at play here.

By default, the iPad will automatically download any apps you download onto the iPhone. In order to prevent this from happening you can:

• Go into the settings app,
• Select "App Store" in the side panel,
• Uncheck the box for "App Downloads"

You may also need to do this on your iPhone. And from this point the ipad won't download apps you put on your iPhone and vice versa.

Randywolf244 wrote:

• First you can delete the apps that you don't want on your iPad but that doesn't actually solve the greater issue at play here.

By default, the iPad will automatically download any apps you download onto the iPhone. In order to prevent this from happening you can:

Go into the settings app,

• Select "App Store" in the side panel,

• Uncheck the box for "App Downloads"

You may also need to do this on your iPhone. And from this point the ipad won't download apps you put on your iPhone and vice versa.

Notwithstanding the OPs actual question concerning impact of deleting an App from a device, your statement is perhaps misleading.

Apps will only be automatically installed to devices, if so configured, when initially purchased/installed. Apps will not automatically re-install after deletion.

As you correctly comment, automatic installation of Apps to a device can be inhibited via iPad settings:

Settings > App Store > [Automatic Downloads] App Downloads - set to OFF

Simply delete an App that you don't want from your device:

How to delete apps - Apple Support

Deleting an App from one device will have absolutely no impact upon other your devices.

Deleting an App will remove any related locally stored data. Don't manually delete data.

Manual deletion of files/data/messages from a device may be synchronised between devices. As such, you should only need to remove the App; all related App settings will be automatically removed along with the App from the device - without affecting other devices.