Yes, both Customer.io and RestApp offer a Free Trial.
Customer.io is designed for Large Enterprises, Medium Business and Small Business.
RestApp is designed for Freelancers, Medium Business and Small Business.
Pricing for Customer.io Starts at $100/Month whereas for RestApp Starts at $9/Month.
Some top alternatives to Customer.io includes Outgrow, ActiveCampaign, CleverTap, Moosend, Omnisend, ActiveTrail, Iterable, Hubspot Marketing Hub, Klaviyo, SendGrid, MailChimp, StreamSend, Adobe Marketo Engage and Contactspot.
Some top alternatives to RestApp includes Microsoft SQL Server, ScaleGrid, Oracle Database, Datos Intelligence, Mozart Data, UseSQL, DBeaver, SqlDBM and Dataform.