This tool is used for configuring op amps. It works for inverting and non-inverting configs, with optional input and output offsets. The output includes a graph of a sine wave input and output of the op amp as configured.
There is a version of this tool running at beta.icosalogic.com/op_amp/.
You can also download the files to your local machine, and just click on the index.html file to run the tool in your local browser. This is especially convenient for using the tool when you have no internet connection.
Most of the data fields on the left hand panel can be edited. Once the focus leaves that input element (say, by clicking outside the edit box or tabbing to the next field), all other dependent fields will be updated, including the graphs.
None of the values you enter are saved, either locally or on a remote server. Your data never leaves your machine. If you close the browser page for this tool, the values you entered are discarded.
The tool includes a lengthy description of how all the values are calculated. This was especially useful for me when I was figuring out how op amps work, and hopefully it will be helpful to some other person in the same situation.