SubscribeComponent.tsx

import { inject, observer } from 'mobx-react/native';
// other imports

// because of the @inject line we will get observableStore to our props
// because of the @observer line the component will be rerendered each time store will get updated
@inject('observableStore')
@observer
export default class SubscribeComponent extends Component<{},{}> {
  
  // bla bla bla code
  
  render() {
    // and here is the property!!
    const property = this.props.observableStore.property;
    const smthImportant = this.getSmthImportant(property);
    return (<ChildComponent important={smthImportant}/>);
  }
}