Yes, both Zingtree and Nextiva offer a Free Trial.
Zingtree is designed for Medium Business and Small Business.
Nextiva is designed for Large Enterprises, Medium Business and Small Business.
Pricing for Zingtree Starts at $8/Month whereas for Nextiva Starts at $18.95/User/Month when Billed Yearly.
Some top alternatives to Zingtree includes Nextiva, Dialer360, Call Center Studio, TelebuHub and Truly.
Some top alternatives to Nextiva includes uContact, Call Center Studio and OmniOMS Customer Communication Management Suite.