I'm not ui ux engineer. I just want to hear your opinion/help on where would you (designers) put this grey box or app links, what is your opinion about colors?
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It looks like you started with a template and just slapped the gray box on top of it.
The gray box itself seems to contain regular unstyled blue/purple links. The rest of the page uses plain black text for the links. The visual inconsistency throws the page off balance. Also are those supposed to be buttons the links are on? If so, remove the underline and make sure you add appropriate hover states to the buttons.
The drop shadow on the gray box is also rather overwhelming, and I would suggest making it more subtle by changing it's color or making it smaller (or both). The gray box also uses rounded corner whereas the rest of the elements use sharp, pointed corners.
Keep in mind the yellow, black, and white are kind of the "theme" of the website. It's very minimalistic and clean - the gradient of the gray box really takes away from that.
I would also suggest reading through these questions:
As mentioned above the gray box is out of place and I have some other notes to add in regards to the gray box.