==============================

w pliku build.gradle.kt:
pod kotlinOptions:

    buildFeatures{
        viewBinding = true
    }

==============================

(MainActivity stwórz)activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textViewWaga"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Waga (kg)"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        android:layout_marginTop="16dp"/>

    <EditText
        android:id="@+id/waga"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/textViewWaga"
        android:layout_marginTop="8dp"/>

    <TextView
        android:id="@+id/textViewWzrost"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Wzrost (cm)"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/waga"
        android:layout_marginTop="16dp"/>

    <EditText
        android:id="@+id/wzrost"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:inputType="numberDecimal"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/textViewWzrost"
        android:layout_marginTop="8dp"/>

    <Button
        android:id="@+id/oblicz"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Oblicz BMI"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/wzrost"
        android:layout_marginTop="16dp"/>

    <Button
        android:id="@+id/historia"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="Historia"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/oblicz"
        android:layout_marginTop="16dp"/>

</androidx.constraintlayout.widget.ConstraintLayout>

==============================

(HistoryActivity stwórz) activity_history.xml:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".HistoryActivity">

    <ListView
        android:id="@+id/listViewHistoria"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>

</androidx.constraintlayout.widget.ConstraintLayout>

==============================

MainActivity.kt:

package com.example.myapplication

import android.content.Intent
import android.os.Bundle
import android.widget.Button
import android.widget.EditText
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private val historiaBmi = mutableListOf<String>()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        val wagaEditText = findViewById<EditText>(R.id.waga)
        val wzrostEditText = findViewById<EditText>(R.id.wzrost)
        val obliczButton = findViewById<Button>(R.id.oblicz)
        val historiaButton = findViewById<Button>(R.id.historia)

        obliczButton.setOnClickListener {
            val waga = wagaEditText.text.toString().toFloatOrNull()
            val wzrost = wzrostEditText.text.toString().toFloatOrNull()

            if (waga != null && wzrost != null && wzrost != 0f) {
                val bmi = waga / ((wzrost / 100) * (wzrost / 100))
                val wynik = "Twoje BMI: %.2f".format(bmi)
                Toast.makeText(this, wynik, Toast.LENGTH_LONG).show()
                historiaBmi.add(wynik)
            } else {
                Toast.makeText(this, "Wprowadz prawilowe dane", Toast.LENGTH_SHORT).show()
            }
        }

        historiaButton.setOnClickListener {
            val intent = Intent(this, HistoryActivity::class.java)
            intent.putStringArrayListExtra("historia", ArrayList(historiaBmi))
            startActivity(intent)
        }
    }
}

==============================

HistoryActivity.kt:

package com.example.myapplication

import android.os.Bundle
import android.widget.ArrayAdapter
import android.widget.ListView
import androidx.appcompat.app.AppCompatActivity

class HistoryActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_history)

        val listViewHistoria = findViewById<ListView>(R.id.listViewHistoria)
        val historia = intent.getStringArrayListExtra("historia")

        if (historia != null) {
            val adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, historia)
            listViewHistoria.adapter = adapter
        }
    }
}

==============================