This app allows you to track, in real time, the amount of subscribers of a Youtube channel.
Using the app is very simple. Just search by channels name and select it from the list. In addition to the total number of subscribers, the number of posted videos and total of views are also displayed. You can also highlight channels.
It is important to clarify that all the information used by the application is public and made available by YouTube itself.
I hope this app helps you grow your channel. Good luck!