If developers can't remember the tasks they're working on, then this could be a symptom of two possible problems:
1. There is too much WIP
that there is too much WIP (work in progress) occurring at any given time. Agile methodologies like scrum encourage teams to focus on getting things to the done state as quickly as possible, and working on more than one thing at a time by definition means that you'll get one thing done a lot slower, since effort is expended across the different tasks instead of laser-focused on one.
As an aside, there's also a psychological effect as well, which you can read more about in the article, Multitasking is Killing Your Brain. Additionally, there's a cost to context switching between tasks where it takes a person some time to recall exactly where they left off in the other task.
This effect is similar to what Jeff Sutherland mentions in his book, Scrum: The Art of Doing Twice the Work in Half the Time:
It took twenty-four times longer. If a bug was addressed on the day it was created, it would take an hour to fix; three weeks later, it would take twenty-four hours. It didn’t even matter if the bug was big or small, complicated or simple — it always took twenty-four times longer three weeks later. As you can imagine, every software developer in the company was soon required to test and fix their code on the same day.
As you can see, the cost of context switching is harmful in many areas, and even Joel Spolsky identifies with this in his blog, Joel on Software
"It's easier to fix bugs the same day you wrote the code. It can be very hard and time-consuming to fix bugs a month later when you've forgotten exactly how the code works." - Joel Spolsky, CEO/Founder of Stack Overflow
While you're not specifically mentioning bugs, the idea is similar in that switching tasks involves not only loss of productivity but forgetfulness as well, since there's a limit on the amount of information we can keep in short term memory at any given time.
In short, Cronax's answer is solid. Make sure you have a big screen. That's what we do when we need the sprint backlog to be visible to multiple people, but the problem you're facing can't be solved by technology alone. I strongly suggest taking a look at the amount of work people are doing and make sure they only have two "cards" to talk about in the daily standup:
- The card which they worked on yesterday.
- The card they will work on today.
2. Tasks are broken down so they're too small
If you're sure that multitasking isn't the problem, then consider that tasks may be too small. Ideally, since each task, according to scrum, should be something that can be completed in a day, consider re-examining how the team breaks down tasks. The problem could also be not that people are taking on too much work but perhaps that tasks are simply too small. Larger tasks may be easier to remember than ones that are broken down so small that 8 can be done in a day. One is always easier to remember than eight.