RAM cleaners, boosters or any kind of such apps or Softwares are actually useless on an android device. Yes, of course, many handset manufacturers do provide some cleaner apps bundled with their os. But they are actually fooling the majority of non-techy people with these crap apps. Most built-in cleaners are spam itself.
Actually, the android system itself has a RAM management system to prioritize ram to applications working on the foreground. These so-called ram cleaners are actually doing nothing but stopping and closing applications working in the background. Once there was an app called Greenify which served well for millions of old generation android devices by hibernating apps on the background. But now things changed as newer versions of android has this as a built-in feature. Have you seen any cleaners for iOS devices? They don't need it as iOS apps won't work on the background instead they are using a save the state method. It's just like pausing on the background and resuming on the foreground.
Moreover, these booster cleaner apps will degrade your device performance as it will use memory and it will affect your battery performance drastically.
So don't install such useless apps to boost something on your Android devices.