My iPhone 6 is constantly at around 98% memory utilisation, even when it is running a bare minimum two or three apps (these figures were obtained from the Lirum Info app). The phone runs noticeably sluggishly, and it is not uncommon for apps to crash when attempting processor-intensive tasks.
How can I find out which app or process is consuming so much memory? I wonder if there is one or more rogue processes which are out of control and should be killed? Something akin to macOS Activity Monitor is what I'm looking for.
In an attempt to improve performance, I've tried all of the suggestions listed here, except a full backup and restore. I am beginning to wonder whether an Apple iPhone 6 battery replacement may be beneficial, but before I do so, I would like to do some diagnosis to find out what the performance hog is.