Error says I forgot to add the method getTileCount that accepts chars:

public class ScrabblePlayer {
  private String mHand;

  public ScrabblePlayer() {
    mHand = "";
  }

  public String getHand() {
   return mHand;
  }

  public void addTile(char tile) {
    // Adds the tile to the hand of the player
    mHand += tile;
  }
public String getTileCount()
  {
    String count = "";
    for (char tile: mHand.toCharArray())
    {
      String displayCount = "";
      if (mHand.indexOf(tile) >= 0)
      {
       displayCount += tile;
      }
      count += displayCount;
    }
    return count;
  }  
  public boolean hasTile(char tile) {
   return mHand.indexOf(tile) > -1;
  }
}