No, there are no trustworthy websites to gain followers. Most of them will give you viruses. Tag your pics as much as you possibly can so that other people can see them, but that's really all you can do.
I do not believe there is a website that can get you followers on instagram. But there are still many other ways you can get followers. You can get followers by following 10 people daily. You should also post pictures regularly so people do not get bored and unfollow you. If you like multiple pictures on someone elses instagram account they may possibly give you a shout out. People will see the shout out and go check out your instagram account. You should also give other people shout outs so people will know you are friendly and hopefully follow you. That is all from me. Good luck gaining followers.