I’m worried about my teen’s safety online and have heard about free apps that claim to do this, but most seemed like scams. Is there a legitimate way to set up monitoring on their WhatsApp that they wouldn’t notice, without having physical access to their phone all the time?
Hey Elijah, honest answer: pretty much everything claiming to monitor WhatsApp remotely without physical access at some point is either a scam or malware, full stop. Legit parental control apps (like Bark, Qustodio, mSpy) all require a one-time setup directly on your kid’s phone first. After that initial setup yeah they run quietly in the background, but you’re not getting around that first hands-on step.
Realistically for a teen, Bark is probably your best bet - it flags concerning content rather than showing you every message, which is less creepy and honestly more practical since nobody has time to read thousands of texts. 
Also don’t sleep on the free stuff first: WhatsApp has a linked devices feature, iPhones have Screen Time built in, and shared family Google/Apple accounts give you way more visibility than people realize without spending a dime.