Hello! It looks like you can install spy app from hoverwatch website https://www.hoverwatch.com It is very good software and easy to set up and use. These apps cell Phone Tracker records SMS, call history and audio, camera, locations, WhatsApp, Facebook, SnapChat, Skype, Telegram, Instagram, internet activity, calendar, contacts. Hope it would make sense for you
There are some free spyware apps in Google Play, but be prepared for a lot of ads and you will probably need to download other apps as well to enable each other. I can't speak for the quality or user-friendliness of these apps, because, quite frankly, the one or two I checked out were not interactive-- just a collection of definitions and precautions. I had more success downloading hidden app finders and file managers. My email and education accounts were hacked during mid-terms in Spring, 2016, and I am still dealing with counterfiet apps, redirects, email accounts that are incomplete or inaccessible.
If you're wanting to literally SPY on someone, then you're going to have to splurge on a nannycam and monitor. Keep it appropriate and be aware of the legalities in your region so that you don't break any criminal or civil laws or violate any privacy or terms of service rules of Google, MSN, Yahoo, etc.
The first thing you should do is to get a multichannel number https://katatelecom.com/services/multichannel-number/ , which will greatly increase the trust of customers in you. You will be able to connect all telephone lines in one network and improve the quality of customer service. This will clearly benefit you. I always like it when such integration solutions are provided. They clearly have a positive effect on the entire service process. So he deprives himself of such a chance.