OpenKeyval : OpenKeyval is a completely open key-value data store, exposed as a drop-dead simple web service. The goal is to make this a very easy way to persist d...
kimono : Turn websites into structured APIs from your browser in seconds
Hoppscotch : A free, online, open source API request builder
Pipes : Pipes is a powerful composition tool to aggregate, manipulate, and mashup content from around the web.
npoint.io : JSON storage bins with schema validation
Bluepine is a DSL for defining API Schema/Endpoint with the capabilities to generate Open API (v3) spec, validate API request and serialize object for API response based on single schema definition.