I’m Emil who is an android developer!
I would like to recommend you [b]a very Useful APP: WiFi Router Master - Detect Who is On My WiFi[/b]
We all want to secure our WiFi Router, so no one can connect to our WiFi without owner permission, but sometimes it makes difficult to check who is connected to our WiFi. Sp, to make this task easy a app called WiFi Router Master - Detect Who is On My WiFi, by using this app you can easily manage and check who is connected to your WiFi and you can simply block them by just one click.
You can see all the devices that are connected to your WiFi with the help of this app. From there you can choose known or stranger to allow or block the access to your WiFi connection. You can also see the network real time speed directly from the main page of the app. You will see a clear graph to get a good idea about your WiFi download and upload speed.
Download the WiFi Router App From Here: https://play.google.com/store/apps/details?id=com.router.manager
I really recommend this app to secure your WiFi.