Quartz's debuff bars will also do this. You can't filter it to show only scorch, but it can be made to show only debuffs pertinent to your class. It's what i've always used because I like having bars for things like Nova and Dragon's Breath as well.
DSST requires every mage in your raid to use it to give a correct timer for stacks that you didn't start but afaik know Scorchio is the same about that.
Not sure you will really need either of those mods once 2.3.2 gets released. There was a patch note that said that you would be able to see the debuff be refreshed when it was done by someone else and, while it didn't make it into 2.3, it seems to be active on the current PTR. At least it seemed that way when I was working on Dr Boom and there were other fire mages present, whenever one of the them refreshed the stack it refreshed on my screen as well.
I really like Elk Buff Bars (Ace mod) for this, timer bar > swirly icon imo. Pretty sure there's several mods that do this but I think EBB hits a real sweet spot between ease and power of configuration. This SS shows how one can use EBB to create a set of bars that filters in only buffs / debuffs that you want displayed in that set (above player and target unit frames).