Car dx/update ecm/tcm tool

I know I've spoken a lot about cars on here, but was curious if any other mechanics recommend any universal tool that allows updates for a wide range of cars? For example, lately I've been working on a few Hondas/Nissans and they require software updates to fix various software issues with the ecm/tcm, I'd prefer not to use a limited tool for a specific make as I'm working a lot more lately on a side jobs.

Thanks in advance!

 

Guys come on... Someone must know some car stuff