Naming

Good naming makes it easier to read and understand code.

Consider the following two versions of functionally equivalent code.

List<String> list1 = new ArrayList<>();
for (x : list1) {
    if (x.size() <= 4) {
        list1.add(x);
    }
}
return list1;
List<String> shortFileNames = new ArrayList<>();
for (name : filenames) {
    if (name.size() <= FILE_NAME_LENGTH_LIMIT) {
        shortFileNames.add(name);
    }
}
return shortFileNames;

Which one is more understandable?

To make your code understandable, you need to reveal your intent and avoid disinformation.

Methods which return boolean values should sound like questions.

if (isFileTooLarge(image))

is more readable than

if (checkFileSize(image))

Naming conventions

Examples of good naming

public class WelcomeActivity extends BaseActivity implements WelcomeView {

    public static final int REQUEST_CODE_LOGIN = 147;

    public static final String EXTRA_ACTION = "EXTRA_ACTION";

    @InjectView(R.id.viewExchangeQuote)
    protected ExchangeQuoteView exchangeQuoteView;

    @InjectView(R.id.textSeeDetails)
    protected TextView seeDetailsText;

    @OnClick(R.id.textSeeDetails)
    protected void onSeeDetailsClicked() {
        presenter.onDetailsRequested();
    }

    @OnClick(R.id.loginButton)
    protected void onLoginButtonClicked() {
        presenter.onLoginButtonClicked();
    }

    @OnClick(R.id.registerButton)
    protected void onRegisterButtonClicked() {
        presenter.onRegisterButtonClicked();
    }

    @Override
    public void showCurrencies(List<Currency> currencies) {
        exchangeQuoteView.showCurrencies(currencies);
    }

    @Override
    public void showSellingAmount(String sellingAmount) {
        exchangeQuoteView.showSellingAmount(sellingAmount);
    }

    @Override
    public void showBuyingAmount(String buyingAmount) {
        exchangeQuoteView.showBuyingAmount(buyingAmount);
    }

    @Override
    public void navigateToLogin() {
        Intent intent = new Intent(this, LoginActivity.class);
        startActivityForResult(intent, REQUEST_CODE_LOGIN);
    }

    @Override
    public void navigateToRegister() {
        Intent intent = RegistrationActivity.buildIntent(this);
        startActivityForResult(intent, REQUEST_CODE_REGISTER);
    }
}
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
            xmlns:tools="http://schemas.android.com/tools"
            android:layout_width="match_parent"
            android:layout_height="match_parent">

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

        <co.infinum.currencyfair.custom.ExchangeQuoteView
                android:id="@+id/viewExchangeQuote"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:visibility="invisible"
                tools:visibility="visible"/>

        <com.ivankocijan.magicviews.views.MagicTextView
                android:id="@+id/textSeeDetails"
                style="@style/TextButton"
                android:padding="8dp"
                android:textAllCaps="false"
                tools:text="@string/see_how_you_save"
                android:visibility="invisible"
                tools:visibility="visible"/>

        <Space
                android:layout_width="match_parent"
                android:layout_height="0dp"
                android:layout_weight="1"/>

        <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:orientation="horizontal">

            <com.ivankocijan.magicviews.views.MagicButton
                    android:id="@+id/registerButton"
                    style="@style/AppTheme.Button"
                    android:layout_width="0dp"
                    android:layout_weight="0.5"
                    android:layout_marginRight="8dp"
                    android:text="@string/register"/>

            <Space android:layout_width="16dp"
                   android:visibility="gone"
                   android:layout_height="1dp"/>

            <com.ivankocijan.magicviews.views.MagicButton
                    android:id="@+id/loginButton"
                    style="@style/AppTheme.Button"
                    android:layout_width="0dp"
                    android:layout_weight="0.5"
                    android:text="@string/login"/>

        </LinearLayout>
    </LinearLayout>
</ScrollView>