On the left of the face emoji, in the top bar, you should see the number of remaining mines. It's not exactly like the version you linked, which should "number found / total", as what I show is simply "remaining mines". Is that what you mean?
Although the number I show is actually a bit sneaky, as I subtract the number of flags placed to the total number of mines. So if you were to place more flags than mines, you'd see a negative number. (which I realise as I type that your version is similar, as the number can also go above the total).
Actually I'm more interested in the game board. If a space has (say) 3 mines next to it, then the numeral 3 will appear (as today). However, when I add a flag next to it, then the count should go down to 2 -- i.e. the number is always the number of mines minus the number of flags. It takes a bit of getting used to when first using that mode, but it becomes much quicker after a while as there is no more checking that a cell with a '4' has 4 flags around it, so all the other adjacent cells are safe. The countdown rule means that a cell with 0 in it, all the open adjacent cells are safe (assuming that the flags are in the right place!!).
Interesting. Thank you for explaining, I understand now.
I'm more leaning toward not adding more options, as I'd like to keep the game as simple as possible, but nevertheless I'll have a think, it might be worth it.
Although the number I show is actually a bit sneaky, as I subtract the number of flags placed to the total number of mines. So if you were to place more flags than mines, you'd see a negative number. (which I realise as I type that your version is similar, as the number can also go above the total).