MainActivity

package com.example.mgarner.blankslate;

import android.os.Handler;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private EditText mEtInput;
    private Button mBtnSubmit;
    private TextView mTvLabel;
    private Handler mTextHandler;
    private ArrayList<String> mTextArray;
    private Runnable mTextDisplayRunnable;
    private boolean mShowingText = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mEtInput = (EditText) findViewById(R.id.main_activity_et_input);
        mBtnSubmit = (Button) findViewById(R.id.main_activity_btn_submit);
        mTvLabel = (TextView) findViewById(R.id.main_activity_tv_label);
        mTextHandler = new Handler();

        mTextDisplayRunnable = new Runnable() {
            
            @Override
            public void run() {
                if (mTextArray.size() > 0) {
                    mShowingText = true;
                    mTvLabel.setText(mTextArray.get(0));
                    mTextArray.remove(0);
                    mTextHandler.postDelayed(this, 1000);
                } else {
                    mTvLabel.setText("");
                    mShowingText = false;
                }
            }
        };
        mTextArray = new ArrayList<>();
        mBtnSubmit.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.main_activity_btn_submit) {
            //handle submit
            String textInput = mEtInput.getText() != null ? mEtInput.getText().toString() : "";
            mEtInput.setText("");
            showText(textInput);
        }
    }

    private void showText(String textInput) {
        mTextArray.add(textInput);
        if (!mShowingText) {
            mTextHandler.post(mTextDisplayRunnable);
        }
    }
}

LGTM