Absolutely fantastic work.
Thanks.

EDIT: Will be great have the possibility to store different CSS styles.

How do I access the formatted bookmarks page now? about:mybookmarks doesn't work anymore, I also tried about:bookmarkshome.

Other then that, best bookmarks add-on on the internet.

Very useful extension, especially to organize many bookmarks.
Could maybe add option for more columns (max 5 at present)

以前のバージョンである「MyBookmarks」の時代からずっと使っている。これをホームに設定し、Firefoxの起動ランチャー画面として使ってきた。ブックマークを300以上登録している私にとっては欠かせないアドオンだ。「MyBookmarks」と使い勝手が変わったが、Firefox57の仕様変更に起因するもので、やむを得ないと思われる。今後も提供を続けてほしい。

Thanks for porting MyBookmarks to WebExtensions.

Would it be possible to make it an option to open links in the same window instead of using hard coded target="_blank"?

Thanks for the job.
But only 3 columns...
1_2_4_5 not working

thanks for your work, please do not give up ....

What does BookmarksHome offer me?

Well I have literally hundreds of bookmarks stored in FF, neatly organized in folders, but getting to the ones I use regularly required me to go (painfully) though that folder structure (try to get to the third level in the folder structure without at least once miss it!).

No longer with BookmarksHome: one click on the BookmarksHome-icon and a browser-tab is opened with my favorite bookmarks. I typically have 4-5 bookmark-folders that I'm using regularly (e-mails, bankaccounts, search-engines, etc.).
Through the 'options' of the extension-settings I can activate those folders (at the bottom of the settings-window).
Once done that the bookmarkshome-icon opens a tab displaying these bookmark-folders with all bookmarks they contain.
I now only need two clicks to access my bank-account webpage.
Try it!
I guarantee you that you'll get addicted to this simple extension.

Note:
My life has been so good the last 15 years( or so) because everyday I enjoyed a simple Firefox add-on called MyBookmarks.
However a couple of days ago it turned out that the add-on is no longer supported in the latest versions of FF.
This extension is replacing that add-on and doing exactly what I was using in the (obsolete) add-on.
Ah, I'm so happy that this extension is now available!
Thanks to the author.