Alternatives to Find My Device

No...

Open Source

Prey

Prey is an anti-theft, data security, and device management app with over 10 years of experience in locating lost phones, laptops, and tablets. Available for Android, Chromebooks, iOS, Windows, Linux, Ubuntu, or MAC. All devices are managed under a single account and manageable from the app itself or through the online panel at the website.

Finder

The main function of Finder is to send the location of the smartphone it's installed on when requested. It also has a "tracker" feature (it can’t be activated remotely, only manually). The application is designed to search for missing people or stolen phones. SMS is used for communication because Internet connectivity may be not available. The app has two ways of determining the coordinates: using GPS (must be enabled in system settings!), and using mobile and WiFi network info.

Closed Source

Probably not safe...