[on_the_train]

I try Anki every couple of years because it has an app and can sync. I also tried fsrs and rage quitted after a few tests. These people can get high and mighty on their algos and research. If they'd just add a manual interval mode they'd contribute a lot more to humanity.

[jarrett-ye]

I guess what you need is Set Due Date, which allows you manually schedule cards in Anki.

[on_the_train]

In my own tool I can do "+10%" or "+2 days"

[jarrett-ye]

Good feature! I guess someone could implement it via an add-on of Anki.