The Model Fit Aggregator is a tool I designed for use with Mplus. It allows you to use the model fit information from any model you estimate via maximum likelihood estimation and plug it in (where instructed). The tool will aggregate the information from the raw output and spit out a single line of model fit statistics for you to paste into a manuscript, poster, talk, or other document.
If you wish to compare nested models, feel free. The Aggregator will also allow you to generate fit information for a nested model, and will calculate the difference in chi squares between the two models and test that difference for statistical significance (note that fit information for both models must be present in the worksheet).