Options
The map
Where you have been leaves out Upcoming and Wishlist. Where you are going leaves out everywhere you have been, which is the map to look at while you are planning. Nothing is unmarked either way: every country still opens with its toggles set, and the rest comes back the moment you switch this.
A trip is its stops as dots with a line between them, and the line is dashed by how you travelled where you have said. Trips are drawn at every zoom. Towns are drawn inside the countries you have broken into regions, once about one country fills the screen, and both gain names when you are closer than that. The town list is around a megabyte and is fetched the first time you need it.
The United Kingdom
Counting the United Kingdom once leaves the four nations out of the countries and territories total, so it reads 256 rather than 260. The UN member count is 193 under both, because the United Kingdom is one member whichever way you look at it.
Which flag
Some places have no agreed flag. The app offers the choice rather than picking one for you.
Northern Ireland
Northern Ireland has had no official flag of its own since 1973. Each of these is used by someone to represent it, and none of them is uncontested.
Choosing nothing leaves the patch unfilled, which is the default.
Western Sahara
Western Sahara is largely controlled by Morocco and claimed by the Sahrawi Arab Democratic Republic. Both fly a flag over it.
Choosing nothing leaves the patch unfilled, which is the default.
Your data
Nothing is uploaded yet, so a saved file is the only copy that survives losing this device. The JSON file restores everything. The spreadsheet is for reading and does not import.
Keeping it here
The app asks your browser to keep this collection when the device runs short of room. It reads nothing and it uploads nothing: the whole request is that what is already on this device is not deleted to make space. It is the only thing the app asks for without you pressing something.