Descriptions : Opensignal is a free, ad-free app for mobile connectivity and network signal speed testing.
Features :
+ Speed test for mobile phones and wifi internet
+ Video playback test
+ Connectivity and speed test coverage map
+ Cell tower compass
+ Statistics on the availability of connections
Required Android Versions : Jelly Bean [4.1–4.3.1] - KitKat [4.4–4.4.4] - Lollipop [5.0–5.0.2] - Marshmallow [6.0 - 6.0.1] - Nougat [7.0 – 7.1.1] - Oreo [8.0-8.1]