adding find my friends to android

I have an iPhone 7 and my daughters have iPhone 6s. My husband refuses to join us and has a Brigadier by Kydocera. He and I have tried the 360 location app on our phones with mixed results, but the best app is the Find my friends that I use with my daughters. Is there any way to add my husband into the inner circle that my daughters and I share? Or is there some other app that I can add so that I can have a reasonably good idea where to locate him (and he, me) if it is necessary? Thank you.