Skipperblogs keep track of your achievements during your voyage and records every country you visited.
With automatic tracking (Premium and Pro plan), the country is automatically added to the list; each time your position is reported (except when manually editing the map tracks), the system check if the position is in a new country. It can happen, when sailing along coast of a new country wihtout stopping by, that the country is still added to the list.
With Free plan, you can still use the list, but you need to update it manually.
The visited countries are displayed as flag in the map info and can also be displayed in a widget.
Map infos
Widget
How to add or remove a country?
Go on the page https://www.skipperblogs.com/dashboard/nav/visited-countries to edit the list.
From there you can remove or re-order countries in the list. To add a new one, simply select one from the bottom dropdown select and it will be added at the end of the list.
Don't forget to save your changes!