Genymotion
Android emulator in the cloud and on the desktop
WireMock
API simulation and HTTP mocking
Mockoon
Local mock REST APIs with desktop app and CLI
Microcks
API mocking and testing for OpenAPI, AsyncAPI, gRPC, GraphQL and SOAP
Hoverfly
Lightweight open source API simulation
Perforce Delphix
Data delivery, masking and synthetic data for test environments