Here are services that can be sold with shopify with example apps https://www.shopify.com/blog/12-things-to-sell-on-shopify-other-than-products#services https://www.shopify.com/partners/blog/105305158-8-merchant-driven-ideas-for-your-next-shopify-app
Apps that does not have “Free plan available” can not be installed on test stores. “Upgrade your account” will be shown for all apps that charges per month or have 7-day free trial.
My app: Move tickets
my app: Populate with sample data generation
Populate with sample data using faker gem https://community.shopify.com/c/Shopify-Design/Populating-development-store/td-p/46116
Similar to Simple Sample Data https://apps.shopify.com/simple-sample-data which has permissions to:
View Shopify account data Manage products Manage orders Manage customers View other data