Be very careful when using any kind of software for traffic, because sooner or later Instagram will discover it and forbid it. Instagram has very strict policies for this.
Instead, like all the others recommended, focus on the QUALITY content. Only quality and interesting publications will bring you followers. Some companies can start contacting you even with a few thousand followers. To earn a decent amount of money, you may have more than 20-30K followers, as more and more companies would contact you and have a larger audience to promote offers.
Also, be in order to get followers and tastes. Be really active on Instagram yourself. Go and, like the photos of other people, comment (only "natural" comments), follow the others. Instagram has rules that you may like 300 photos, or follow 20 people in an hour, if more, your account will be at risk of being banned, as it will probably look like spam. So stay active but do not overdo it.