Please try out sparql-fiddle - an online app and gerneral purpose library for using SPARQL with Solid PODs, in-memory strings, and other sources.
The online app allows you to create RDF and SPARQL or load them from Solid, run the queries view the results, edit either the data or the query, re-run, rinse and repeat. It includes a few examples, more coming.
The code library is entirely based on rdflib.js so can run either in a browser or from the command line. It provides functions to run SPARQL from a variety of sources with a flexible API that supports retrieving results as text, HTML or as various kinds of data structures. It also includes a way to store, retrieve, and run a library of queries.
I’d really like feedback both on the API and on the ontology I propose for a community-based sharing of queries (see the README).
Caveats: 1. the SPARQL is the subset of SPARQL supported by rdflib.js. 2. I have not (yet) implemented a planned secondary fetcher which will allow the library to support full endpoint querying with traversal of multiple URLs.