Yes, both ShareSpring and Later offer a Free Trial.
ShareSpring is designed for Large Enterprises, Medium Business and Small Business.
Later is designed for Individuals, Freelancers, Large Enterprises, Medium Business and Small Business.
Pricing for ShareSpring Starts at $50/Month whereas for Later Starts at $12.50/Month when Billed Yearly.
Some top alternatives to ShareSpring includes Zoho Social, Crowdfire, SocialBee, Social Media Wall, Buffer, Planable, Later, SocialBu, Aggreto, Broadcast, Social Mako, CloudSocial, SocialHub, Send Social Media and Posted.
Some top alternatives to Later includes Zoho Social, Crowdfire, SocialBee, Social Insight, Postcron, SocialMgr, SocialPilot, Sked Social, Socialdraft, InoSocial, CloudSocial, SocialHub and SocialGest.