Safest or best free iPhone app to test Wi-Fi strength? [View all]

There are several free apps I could use but I don’t know which one is the safest one to use and all I want to do is test signal strength to a ring device and a KWIKSET halo lock.

I am pretty sure the sign strength is really good but the Kwikset wants to constantly not stay connected and the process to delete the lock add it back on and reconnect it is not easy.

Thank you in advance for anyone who wants to help me!

By the way I have a Xfinity XB8 speed of 800 and it is 33 feet away from the devices in a straight unobstructed line hallway but it is on a mantle 18 inches around the corner from the hallway. The phone has a perfect signal when I stand there and so does my laptop and iPad and my wife’s phone etc.