A free program for Android, by Social Blade.
Live Subscriber Count – Social Blade is an extension that allows you to track the number of subscribers for any YouTube channel in real time. It is available in the Chrome Web Store and can be used on desktop.
If you have a YouTube channel and are looking to expand your audience, you can use this tool to track your subscribers in real time and get an accurate count of the number of subscribers. It is compatible with Chrome and Firefox browsers.
To get the most accurate count, it will take into account the latest data from the YouTube API. It is not only limited by the number of subscribers, but you can also track the growth of your channel in real time.
You can save the data you want to track for later use and even share it with your friends.