Influence.co is described as 'Free tools to discover influencers on Instagram, Twitter, Blogs, YouTube, Pinterest and SnapChat'. There are four alternatives to Influence.co, not only websites but also apps for SaaS. The best alternative is Buzzsumo, which is free. Other great sites and apps similar to Influence.co are Bloggerwork (Freemium), Social Animal (Freemium) and Influence Hunter (Paid).
Influence Hunter is an Influencer Marketing platform designed for startups and small businesses. They specialize in finding micro-influencers who will post on behalf of brands in exchange for a free product or service.