Is there an Excel add-in to check where the spreadsheet is lagging the most?

I've made a spreadsheet over a period of time with multiple complex formulas and a lot of thread calculations.

Now the sheet has gone slow even when the primary data is not there.
I can't point to a single formula which is taking the most load.
I wanna optimize the file, by updating or removing the formulas which are causing the most lag.
I saw some add in before that could analyze the whole sheet. Can't remember.

Is there one? Can you send me the link to it?
PeterBartholomew1 SergeiBaklan Detlef_Lewin Riny_van_Eekelen