Quick and dirty RPC console mostly aimed at working with CryptoNote based currencies.
Use File/Settings menu to configure end point.
Left hand screen is a console style entry. Type in commands with space delimited params; eg, to use getblockheaderbyheight type: getblockheaderbyheight height=1 Press enter to run.
On the right hand side are two text boxes. The top defaults to the last entered command. The bottom is autogenerated input json (created from the above but can be overwritten if you prefer to work with json) - press execute to run.