I just want to share a website I made back in 2014 when I was studying Mnemonica (for the second time). Here it is: https://bezhermoso.github.io/mnemonica/
It allows you to go through the stack for practice, or quickly look up a card in position (or vice-versa). It also have 3 quiz modes: value, card, or both. It is pretty basic, but I found it handy when I wanted to train when I don't have a deck with me but have a smartphone handy (yes, it's "mobile-friendly" as we'd like to call it in tech. Just swipe!).
I know there are mobile apps out there already. However I didn't find them to my liking so I made this. I'm not claiming this is better, just a different form that I made that works for me. Maybe it works for you, too.
I am actually currently working on upgrading it now that I have some free time. If you like it and would like to see a feature, let me know and I'll see if I can work it in! Right now, current list of features is improving the overall design, making it more usable on mobile phones (it needs improvements in that department), and ability to make it work offline i.e. you can bookmark it on your phone and come back to it anytime you like, even when you don't have an internet connection). Hopefully I can roll those out in a month or so.