Hi all, this is my first post for a while, I used to be known as TommyTurtle 
I’ve been getting back into card and number memorisation with the help of this app, and really enjoying it. I’ve had a bit of an attitude shift towards just enjoying the process, and the little worlds that I’m creating in my head, rather than worrying too much about speed or progress towards a certain goal.
My systems are:
Numbers
Essentially the Ben System, with a few changes:
4 is D, because I just find that Rs cause too many problems at the end of a word/syllable.
I’ve shifted the vowels around cos I can’t help seeing 1 as I and 3 as E.
So my vowels are:
0 = oh/oi, 1 = ih, 2 = ah/ar, 3 = eh
4 = o/or, 5 = uh, 6 = ay/air,
7 = ee/ear, 8 = oo/ou, 9 = igh/ire.
Cards
Essentially the Katie System, which I find really elegant and flexible.
Adaptations:
4 = D (as in my adapted Ben System)
Jack at start of card pair = G/H
Jack at end of card pair = G only
Queen = B (I think of “Queen Bee” 
)
King at start of card pair = R
King at end of card pair= R/nothing
I’ve also changed how suit pairs map on to vowel sounds a bit, in a way that makes sense to me.
Binary
The same as Numbers, after converting 3-digit binary strings into numerals 1-7.
I find the above systems really fun to use, especially because you can make up word associations “on the hoof” without having to commit 1552 “images” to memory.
My record so far for card memorisation is 3:26 for a full deck. So I wouldn’t win any competitions, but I am massively enjoying the pastime. 