Network Monitor Mini Pro : KF Software House

This is a mini network monitor for your phone. It monitors the upload and download speed per second. It will always stay in the corner of your phone's screen. You can set the indicator to any corner of the screen, customize the color and transparency of the indicator. You can record the live network information for your WiFi / 4G / 5G network speed!

PRO version features:
• Adjustable Kilo Value
• Adjustable Decimal Places (Please turn it off if you have flickering problem)
• Normalize VPN / proxy / loopback traffic
• Custom Readings Location
• Show on Status Bar
• Hide Readings when there is No Traffic
• Hide when Specific Apps are Running
• Hide when Day Dreaming (screen saver - 4.2+)
• Beta Test: Traffic Breakdown Mode (for supported devices only)

PRO version support auto-hides when there is no traffic, hides monitor for specific apps, and it is ad-free.

Free version:

https://play.google.com/store/apps/details?id=info.kfsoft.android.TrafficIndicator