MainActivity.java
==================

package whatsapp.com.example.android.julian.myapplication;
import android.content.Intent;
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 android.widget.Toast;

import com.backendless.Backendless;
import com.backendless.BackendlessUser;
import com.backendless.async.callback.AsyncCallback;
import com.backendless.exceptions.BackendlessFault;

public class MainActivity extends AppCompatActivity {
    Button btnLogin,btnRegister;
    EditText txtName,txtPass;
    TextView ttlLogo;
    MainActivity context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //make a connection to BackEndLess
        Backendless.initApp(this,
                getResources().getString(R.string.app_id),
                getResources().getString(R.string.android_id),
                getResources().getString(R.string.app_v));
        setPointer();
        // loginUser();
    }


    private void setPointer()
    {
        //context
        this.context=this;
        //pointers
        btnLogin=(Button)findViewById(btnLogin);
        btnRegister=(Button)findViewById(btnRegister);
        txtName=(EditText)findViewById(R.id.txtName);
        txtPass=(EditText)findViewById(R.id.txtPass);
        ttlLogo=(TextView)findViewById(R.id.ttlLogo);
        ttlLogo.setText("Camel Studio");

        //listeners
        btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //check user name and password
                String uName=txtName.getText().toString();
                String uPass=txtPass.getText().toString();
                if (uName.length()<1 || uPass.length()<1)
                {
                    Toast.makeText(context, "you must provide user and password", Toast.LENGTH_SHORT).show();
                    return;
                }
                //check login
                Backendless.UserService.login(uName, uPass, new AsyncCallback<BackendlessUser>() {
                    @Override
                    public void handleResponse(BackendlessUser response) {
                        startActivity(new Intent(context,Login.class));
                    }

                    @Override
                    public void handleFault(BackendlessFault fault) {
                        Toast.makeText(context, "Error:"+fault.getMessage(), Toast.LENGTH_SHORT).show();
                    }
                });
            }
        });
        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivity(new Intent(context,Register.class));
            }
        });
    }
}



Login.java
============
package whatsapp.com.example.android.julian.myapplication;

/**
 * Created by android on 22/12/2016.
 */
public class Login {
}


AndroidManifest.xml
=======================
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="whatsapp.com.example.android.julian.myapplication">
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".Register"></activity>
    </application>

</manifest>



app
======
apply plugin: 'com.android.application'

android {
    compileSdkVersion 25
    buildToolsVersion "25.0.1"
    defaultConfig {
        applicationId "whatsapp.com.example.android.julian.myapplication"
        minSdkVersion 19
        targetSdkVersion 25
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    compile 'com.android.support:appcompat-v7:25.0.0'
    compile 'com.android.support:design:25.0.0'
    testCompile 'junit:junit:4.12'
    compile 'com.backendless:backendless:3.0.20.1'
}


activity_register.xml
========================
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layoutDirection="rtl"
        android:textDirection="rtl">

        <EditText
            android:id="@+id/txtUserName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/enter_user_name"

            />

        <EditText
            android:id="@+id/txtEmail"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtUserName"
            android:hint="@string/enter_email" />

        <EditText
            android:id="@+id/txtPhone"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtEmail"
            android:hint="@string/enter_your_phone_number" />

        <EditText
            android:id="@+id/txtPassword2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtPhone"
            android:hint="@string/enter_password" />

        <EditText
            android:id="@+id/txtPassword3"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtPassword2"
            android:hint="@string/confirm_password" />

        <CheckBox
            android:id="@+id/checkbox"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/btnRegisterUser"
            android:layout_marginTop="10sp"
            android:text="אני מסכים" />

        <TextView
            android:id="@+id/txtView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/btnCancel"
            android:textColor="@color/colorPrimary"
            android:layout_marginRight="10sp"
            android:text="תנאי השימוש"
            android:textSize="15sp"


            />

        <Button
            android:id="@+id/btnRegisterUser"
            android:layout_width="150dp"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtPassword3"
            android:layout_marginTop="35dp"
            android:text="@string/Register_button" />

        <Button
            android:id="@+id/btnCancel"
            android:layout_width="150dp"
            android:layout_height="wrap_content"
            android:layout_below="@id/txtPassword3"
            android:layout_marginTop="35dp"
            android:layout_toEndOf="@id/btnRegisterUser"
            android:text="@string/btn_cancel" />


    </RelativeLayout>

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:gravity="center"
        android:text="הרשמה"
        android:textSize="32sp" />

</LinearLayout>



Register.java
===============
package whatsapp.com.example.android.julian.myapplication;

import android.content.Context;
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 android.widget.Toast;

import com.backendless.Backendless;
import com.backendless.BackendlessUser;
import com.backendless.async.callback.AsyncCallback;
import com.backendless.exceptions.BackendlessFault;

public class Register extends AppCompatActivity {
    Button btnRegister,btnCancel;
    EditText txtUname,txtUpass,txtUpass2;
    TextView txtView;
    Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_register);
        setPointer();
    }

    private void setPointer()
    {
        //context
        this.context=this;
        //pointers
        btnCancel=(Button)findViewById(R.id.btnCancel);
        btnRegister=(Button)findViewById(R.id.btnRegisterUser);
        txtUname=(EditText)findViewById(R.id.txtUserName);
        txtUpass=(EditText)findViewById(R.id.txtPassword2);
        txtUpass2=(EditText)findViewById(R.id.txtPassword3);
        txtView=(TextView)findViewById(R.id.txtView);
        txtView.setText("Camel Studio");
        //listeners
        btnCancel.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                finish();
            }
        });
        btnRegister.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (checkData())
                {
                    BackendlessUser newUser = new BackendlessUser();
                    newUser.setEmail(txtUname.getText().toString());
                    newUser.setPassword(txtUpass.getText().toString());
                    Backendless.UserService.register(newUser, new AsyncCallback<BackendlessUser>() {
                        @Override
                        public void handleResponse(BackendlessUser response) {
                            Toast.makeText(context, "User Registred...", Toast.LENGTH_SHORT).show();
                            finish();
                        }

                        @Override
                        public void handleFault(BackendlessFault fault) {
                            Toast.makeText(context, "Error"+fault.getMessage(), Toast.LENGTH_SHORT).show();
                        }
                    });
                }
            }
        });
    }

    private boolean checkData()
    {
        //if user update fields
        if (txtUname.getText().toString().length()<1 ||
                txtUpass2.getText().toString().length()<1 ||
                txtUpass.getText().toString().length()<1)
        {
            return false;
        }

        //if password are equals
        if(!txtUpass.getText().toString().equals(txtUpass2.getText().toString()))
        {
            Toast.makeText(context, "Password not match..", Toast.LENGTH_SHORT).show();
            return false;
        }

        return true;
    }

}


welcome.xml
===============
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/rings"
            android:id="@+id/imageView3" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/bar_micva"
            android:id="@+id/imageView4" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/birthday" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/brit"
            android:id="@+id/imageView" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1">

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/work_party"
            android:id="@+id/imageView2" />

        <ImageView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_weight="1"
            android:background="@drawable/ravakot" />
    </LinearLayout>

</LinearLayout>


activity_main.xml
===================
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layoutDirection="rtl"
    android:textDirection="rtl">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:orientation="vertical">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:text="LOGO"
            android:textSize="100sp">

        </TextView>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:orientation="vertical">

        <EditText
            android:id="@+id/txtUserName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/enter_user_name"
            android:inputType="text"
            android:textSize="22sp" />

        <EditText
            android:id="@+id/txtUserPassword"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:hint="@string/enter_password"

            android:textSize="22sp" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="150dp"
        android:orientation="vertical">

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/btn_login"
            android:background="#00BFFF"
            android:textColor="#ffffff"
            android:textSize="32sp"
            android:id="@+id/btnLogin"
            android:layout_marginBottom="20dp"/>

        <Button
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/Register_button"
            android:background="#00BFFF"
            android:textColor="#ffffff"
            android:textSize="32sp"
            android:id="@+id/btnRegister"/>
    </LinearLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

    </LinearLayout>
</LinearLayout>