The last version of WhatsApp that worked on iOS 9 (which includes your iPad 2 running iOS 9.3.5) is . However, since May 2021, that version can no longer connect to the WhatsApp servers. You will get an error saying your device is out of date.
. Because the iPad 2 cannot be updated past iOS 9.3.5, you must use workarounds to access your messages. WhatsApp Help Center Method 1: Use WhatsApp Web (Recommended) whatsapp for ipad 2 ios 935 updated