Get Instagram followers by following and unsubscribing?

There are such sites on İnatagram where you subscribe to them and then subscribe again to get followers. Do you know which sites work really well?

I've only ever lacasadapapel, ninja, lisaandlena, ursulolita, fortnite

This works on all sides with many followers. You could add Justin Bieber and Cristiano Ronaldo to your "collection".