Well you can run Fm whatsapp on your iPhone that too without jailbreak but not more than 7 days after that you won't even able to open that whatsapp as Apple verifies certification every week and after a week it won't allow you to open the app as the app is not been downloaded from the official app store
And if we talk about a jailbreak process
In jailbreak after ios 10 jailbreaks aren't that much stable sometimes the Cydia app hangs and sometimes other tweaks make your phone restart again and again I've used Apple with and without jailbreak believe me don't waste your time into struggling for
Fm whatsapp instead use the original whatsapp from the AppStore or get the android phone in which getting whatsapp plus is mere of two minutes thing