I'm amazed that A) I haven't looked for this sooner, and B) I couldn't find something that does this.
My phone is an non-rooted LG Stylo 3 Plus, Android version 7.0 Software version TP45010m.
(Also, if anyone knows how to root this phone specifically, I'd like to hear it... I haven't been able to find a method that works for LG Stylo 3 Plus and have seen that this phone specifically is unable to be rooted.)
Any time my 80-year-old mother asks me to help her with something on her smartphone (Does the day of the week end with "y"?), I tap the □ button to see her recent screens. She generally has like 47 recent cards listed there, as she never swipes them away or clears the list.
I'm aware of the concept that (generally speaking) these are more or less shortcuts to apps that have run, and that they (generally) use no memory while sleeping in this state, so swiping them away often won't conserve significant resources.
I'm also aware that I can "CLEAR ALL" cards (the button can be seen in my animation), but I don't want to do that, either.
The problem is that this is supposed to be an "easy" way to jump back and forth between apps that you use often, right? Doesn't it defeat that purpose if there are 47 cards to look through? Easier just to find the app in the app drawer and "restart" it.
I looked, first on playstore, then just searched the internet at large for something that would simply limit the number of recent cards on that screen to, say 5. Whenever you have 5 cards (or 10 or whatever) and you open a new app, the oldest would disappear.
I found a bunch of stuff that would "kill" an app or all apps, but this is counterproductive in my case, right? Doing this would reduce battery charge life because I would be using resources to turn it off, then use more resources to create a new instance of it the next time I want to use it—as opposed to just letting it sleep, where it uses very little resources and comes back to life quickly.
Bonus, same thing goes for her Chrome browser. 63 open tabs??!!??!! I found how to close all open tabs, but it would be nice to only have the 5 most recents there and remove the older ones.