app.js

import React, { Component } from 'react';
import Progress from 'components/Progress';

class App extends Component {
  state = {
    count: 10
  }

  render() {
    return <div>
      <div>
        O progresso é {this.state.count}
      </div>

      <Progress value={this.state.count} />
    </div>
  }
}

export default App;