wp-custom-routes.php

<?php

/**
 * Configure your routes here
 * Slugs and page titles are translatable
 */
$routes = array(
  "my-profile" => array(
    "slug" => __( "my-profil" ), 
    "title" => __( "My profile" )
  ),
  "login" => array(
    "slug" => __( "user-login" ), 
    "title" => __( "Log in" )
  ),
  "logout" => array(
    "slug" => __( "user-logout" ), 
    "title" => __( "Log out" )
  )
);

/**
 * Add endpoints
 */
add_action('init', function() use($routes) {
  foreach ( $routes as $route => $route_opts ) {
    add_rewrite_rule(
      sprintf( "^%s/?", $route_opts['slug'] ),
      sprintf( "index.php?pagename=%s", $route ),
      'top'
    );
  }
});

/**
 * Hook up page templates. 
 */
add_filter('template_include', function($template) use($routes) {
  global $wp_query;

  if ( in_array( get_query_var('pagename'), array_keys($routes) ) ) {
    // http://wordpress.stackexchange.com/q/228466/23829
    $wp_query->is_404 = false;

    $template = sprintf(
      // Template files need to match this format:
      // page-templates/page-*route*.php
      "%s/page-templates/page-%s.php",
      get_template_directory(),
      get_query_var('pagename')
    );
  }

  return $template;
}, 10, 1);

/**
 * Add custom page titles
 */
add_filter( 'document_title_parts', function($title_arr) use($routes) {
  foreach ($routes as $route => $route_opts) {
    if ( get_query_var( 'pagename' ) === $route ) {
      $title_arr['title'] = $route_opts['title'];
    }
  }

  return $title_arr;
}, 10, 1 );