TO THE DEVELOPER:
---There is a problem, the current thumbnail images do not show at all. So you end up with grey rectangles instead of a rectangle with the current thumbnail image!
It seems to correct itself when I click on the grey thumbnail then I see the current image BUT it is not a the current thumbnail image that is immediately recognizable and therefore that is much better than the image shown when you click on the grey rectangle link.
If you could allow to show the current thumbnail image instead like it is shown on the original new tab, then it would be much better I believe.

---Could you allow the Recently Closed Tabs to be located at the top or at the bottom of the page. I personally prefer at the bottom of the page.
Could you allow also to add 1 or more rows and columns for these Recently Closed Tabs, as I have a 4K 43-inch monitor and I have a lot of space both vertically and horizontally I could say.

---So, could you allow also blank lines (1 or more) above the Recently Closed Tabs when it is located at the bottom of the page and below the Recently Closed Tabs when it is located at the top of the page, as currently there is simply no space at all just below the Recently Closed Tabs.

---You could also add a quick explanation in Options where you say something like the following. Open a new tab, click at the top right on the icon called Personalize New Tab and select the options that you want to use to customize your new tab page the way you want it.
Because at the very beginning, I was kind of lost until I realized that I had to open a new tab to see this Personalize New Tab! I know, it is obvious but...! If I was lost, so probably quite a few other people are likely to be too.

---A HUGE PROBLEM!!
You might think it is dead easy to add new links on the new tab with your addon? Well, it was not and I will explain. For example, I have say 4 rows and 10 columns of links that are on this new tab page. I go to the end on the first row first rectangle from the left to add a new link and it simply does not add it at all!! That is how frustrating it is!!
---BUT I discovered what really happened. I had 10 columns, 4 rows and I was tryting to add 2 more links and so I opened the page for each and used the New Tab Tools icon and then pin to the New Tab Page and it was greyed. What happened is that the 2 links I could not add them because they were already there on the new tab page but they were behind existing rectangle links so I could not see them! When I moved 2 links to the next row, then I could get the 2 links I wanted to add because they were already there on the New Tab page!! Probably a bug I would assume.

---To add links on the new tab page, it would be much better that you allow, if possible to do, the following feature.
On Firefox, I have a button called Show sidebars where, when clicked, I see at the left all my bookmarks.
I created a folder of links that I want to place on the new tab page with your addon. I could select them in the folder, do a copy and go to your tab page, select by right-clicking the mouse the option paste and I paste all the selected links onto your new tab page and it would add them all on this new tab page. That dead simple would be a dream.

By the way, you seem to have a Firefox addon called Better Reader but it does not show as an addon on the Firefox addons page at https://addons.mozilla.org/en-US/firefox/

Many thanks for this New Tab Tools addon. It is very good. I particular like the option of being able to put a background photo of your choice.

Kind Regards
Michael