Your WhatsApp data should be imported successfully. Tap Start to import your data when prompted, and allow the process to complete. When you reach the home screen, open WhatsApp and log in using the same phone number used on your iPhone. Continue with the setup of your Galaxy phone.

Tap Start on your iPhone and wait for the process to complete. When prompted, scan the QR code shown on your Galaxy phone using the iPhone’s camera. Select the data you wish to transfer, including ' Data from iPhone apps' and tap Transfer. (You might be prompted to install WhatsApp if you do not already have it installed). On your iPhone, tap 'Trust' on the pop-up. Connect by cable to your iPhone when prompted (your phone must be turned on). Under Select a source, select iPhone/iPad. You will be asked 'What should this phone do?'. Step 6 Tap on the types of data you want to clear and remove.

From your Samsung phone's Home screen, go to Settings > Accounts and backup > Bring data from old device. In order to free up your iPhone storage, please follow this article to clear WhatsApp app.

Free whatsapp for iphone 6