You can try it here:
Although it is not as mature as other explorers, it is pure frontend. It connects directly to a grpc-web libra AC service which anyone can host using Envoy proxy.
Thanks to gopher-libra, it also does all the crypto verifications locally, so that you can stay secure even though you are using http without TLS.
You can also download and unpack the files here: http://pg.wutj.info/web_client.zip
And then host it on your own computer, using python:
python -m SimpleHTTPServer 8080
Then visit http://localhost:8080/
BTW, I’m not a frontend expert. Your contributions are very welcome. The code is hosted as an example here: https://github.com/the729/go-libra/tree/master/example/web_client