I am interested in the life of Apollonius of Tyana, but the account by Philostratus seems a little late. Are there any other accounts of Apollonius outside Philostratus, either before him, or independent of him?
So after digging around the web, I could really find any accounts of him before Philostratus. According to Wikipedia, the realist account of him was written by Philostratus. So unless we discover older writings or mentions of him, then no. This is the earliest ever written piece of him. And plus it is very detailed so be sure to check it out.