This tool seems to do a pretty good job.

The company’s Mobile Threat Hunting feature uses a combination of malware signature-based detection, heuristics, and machine learning to look for anomalies in iOS and Android device activity or telltale signs of spyware infection. For paying iVerify customers, the tool regularly checks devices for potential compromise. But the company also offers a free version of the feature for anyone who downloads the iVerify Basics app for $1. These users can walk through steps to generate and send a special diagnostic utility file to iVerify and receive analysis within hours. Free users can use the tool once a month. iVerify’s infrastructure is built to be privacy-preserving, but to run the Mobile Threat Hunting feature, users must enter an email address so the company has a way to contact them if a scan turns up spyware—as it did in the seven recent Pegasus discoveries.