Power rankings/grades

First year running our home league and wanted to add a little something after the draft. We are on sleeper and know people really enjoyed the grades on yahoo before we changed.
does anyone know of a website that would offer this or would i be better off just doing like a power ranking? I don’t have a whole lot of time otherwise i would just break down the teams myself!

Fantasy Pros does a power ranking system, but might only be included in the paid premium service.