Yes, both Datadog APM and Rely.io offer a Free Trial.
Datadog APM is designed for Freelancers, Large Enterprises, Medium Business and Small Business.
Rely.io is designed for Large Enterprises, Small Business, Medium Business and Individuals.
The starting price of Rely.io begins at $20.00per user / month when Billed Yearly, while pricing details for Datadog APM are unavailable.
Some top alternatives to Datadog APM includes Retrace, Scout APM, New Relic APM, Nastel AutoPilot, AppDynamics, Dynatrace, Instana, Thundra APM and APImetrics.
Some top alternatives to Rely.io includes and undefined.