If you're on Android use grayjay, if you're on Linux use freetube. You can follow channels on both of those.
If using grayjay and you can afford it please do pay for the license; you're not technically required; it's based on the honor system, but it helps the developers at FUTO work on it and it helps them donate to other FOSS projects.
If you use freetube please donate to them, even a dollar, the developers will greatly appreciate it.