Based on your description alone I don't think it's legit. 500 PHP sign in bonus? That alone makes it fishy enough. I would understand if it was a referral bonus, but not if it's only a sign in bonus like you said. Also, maybe you mean no withdrawal fee? As transaction fees are always present on whatever cryptocurrency(besides IOTA).
Ask your friend, why look for an alternative is Bittrex is working fine?
By the way can you link us the irontrade app? I don't think that's affiliated with
https://irontrade.com/