If you're at high risk of being targeted by mercenary spyware, or just don't mind losing iOS features for extra security, the company's restricted mode is surprisingly usable.
https://www.wired.com/story/apple-lockdown-mode-hands-on/?utm_source=dlvr.it&utm_medium=blogger
https://www.wired.com/story/apple-lockdown-mode-hands-on/?utm_source=dlvr.it&utm_medium=blogger