AutoFitGrid/AutoFitStaggerdGrid is a RecyclerView with a Grid/StaggeredGridLayoutManager which automatically sets the number of columns based on the column width.

auto-fit-grid.xml

<com.package.AutoFitGrid xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/grid_id"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="300dp" />

auto-fit-staggered-grid.xml

<com.package.AutoFitStaggeredGrid xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/grid_id"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:columnWidth="300dp" />

AutoFitGrid.kt

class AutoFitGrid : RecyclerView {
    private var manager: GridLayoutManager? = null
    private var columnWidth = -1

    constructor(context: Context) : super(context) {
        initialization(context, null)
    }

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        initialization(context, attrs)
    }

    constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(
        context,
        attrs,
        defStyle
    ) {
        initialization(context, attrs)
    }

    private fun initialization(context: Context, attrs: AttributeSet?) {
        if (attrs != null) {
            // List the attributes we want to fetch
            val attrsArray = intArrayOf(android.R.attr.columnWidth)
            val array = context.obtainStyledAttributes(attrs, attrsArray)
            // Retrieve the value of the 0 index, which is columnWidth
            columnWidth = array.getDimensionPixelSize(0, -1)
            array.recycle()
        }
        manager = GridLayoutManager(context, 1)
        layoutManager = manager
    }

    override fun onMeasure(widthSpec: Int, heightSpec: Int) {
        super.onMeasure(widthSpec, heightSpec)
        if (columnWidth > 0) {
            // The spanCount should always be at least 1
            val spanCount = max(1, measuredWidth / columnWidth)
            manager!!.spanCount = spanCount
        }
    }
}

AutoFitStaggeredGrid.kt

class AutoFitStaggeredGrid : RecyclerView {
    private var manager: StaggeredGridLayoutManager? = null
    private var columnWidth = -1

    constructor(context: Context) : super(context) {
        initialization(context, null)
    }

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        initialization(context, attrs)
    }

    constructor(context: Context, attrs: AttributeSet, defStyle: Int) : super(
        context,
        attrs,
        defStyle
    ) {
        initialization(context, attrs)
    }

    private fun initialization(context: Context, attrs: AttributeSet?) {
        if (attrs != null) {
            // List the attributes we want to fetch
            val attrsArray = intArrayOf(android.R.attr.columnWidth)
            val array = context.obtainStyledAttributes(attrs, attrsArray)
            // Retrieve the value of the 0 index, which is columnWidth
            columnWidth = array.getDimensionPixelSize(0, -1)
            array.recycle()
        }
        manager = StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL)
        layoutManager = manager
    }

    override fun onMeasure(widthSpec: Int, heightSpec: Int) {
        super.onMeasure(widthSpec, heightSpec)
        if (columnWidth > 0) {
            // The spanCount should always be at least 1
            val spanCount = max(1, measuredWidth / columnWidth)
            manager!!.spanCount = spanCount
        }
    }
}