From what I have experienced this app is broken and not fit for distribution.
I used V1.0 of Globo Upsell for a short time and it worked well enough (although it was by no means perfect - not bad for free though)
I decided to upgrade to V2.0 (the paid version, since the free version of V2.0 actually removes a lot of the useful stuff from V1.0, very cynical move Globo)
V2.0 is a nightmare, nothing works properly (discount function broken, update cart function broken, app formatting on product page very ugly). Contact Customer Support who completely ignored most of the issues I raised and provided a non-coherent solution which I'd already told them doesn't solve anything. Very poorly designed app and useless customer support.
Needless to say I have now removed the app and will try one of their many competitors instead.

having an issue with add to cart. I have got most of this set up. issue i am having is when you add bought together items to cart they don't show up in the cart unless you refresh the page and i can't expect customers to figure that out so i have disabled the app until i hear from someone, if i don't in the next day i will delete the app and try another one. Also, the discount code functions is not working for me aswell.

I used this app for a long time without problems on the template brooklyn. Since some months it shows the recommended products overlapping the product description. I had to switch it off. That's a shame because the logic behind work very well, even better than the other app I am using now.

I used to love this app and recommend it. And then it changed overnight without notice. No more customization and no more manual recommendation in the free version. Furthermore, the pricing presents a 3.99$ option, but when you install the app this option is nowhere to be seen, there is only the 6.99$ option.
And even more, the "Add to cart" button for the bundle doesn't work, the discount doesn't work, the color customization on the cart page is not possible because the boxes are under the bottom of the page... and it's the week-end so it seems there is no one to answer the chat and fix the problems.
I understand that all apps can't be free and that they make apps for a living, that's not a problem, at least when they work. This is not professional.

Will not let me add a manual product - other options seem to work fine but since I cannot choose what items to recommend it isn't useful for me.

HOW CAN THE APPLICATION STOP WORKING FROM ONE DAY TO ANOTHER? IT IS VERY UNPROFESSIONAL, I HAVE TRUSTED YOU AND YOU DO THIS WITHOUT WARNING. I HOPE THEY FIX IT NOW.

Abysmal. It has very big loading times. Sometimes it takes even 15 seconds to load. After uninstalling, it left some junk in the code. Support is also awful, they ask you to let them be a collaborator to your shop. This developer should be banned from the store.

Your software is disgusting, I have uninstalled and there are still residues! Caused my website to function abnormally! I will not dare to use any of your software in the future.

Not recommended. The app worked for a few days then stopped working. If I knew it I would not have downloaded it.

I would leave no stars if I can, this app is not working, or I can't get it to work, and not getting the help I think I need from the team, for many days now I am trying with it and wasting a long time, and I can't make it work!! stay away from it.