Yes, both nandbox and A2Zapps offer a Free Trial.
nandbox is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
A2Zapps is designed for Individuals, Large Enterprises, Medium Business and Small Business.
Pricing for nandbox Starts at $49/Month whereas for A2Zapps Starts at $1/Month.
Some top alternatives to nandbox includes Nwicode, Bizness Apps, GitHub, Apphive, AppInstitute, Native, AppMaster.io and Codeless.
Some top alternatives to A2Zapps includes AppElixir, Nwicode, GitHub, Apphive, Native, 2OS App Builder, AppMaster.io and Codeless.