Best to focus on your own knowledge both with sports and any game of luck casino games, instead of using an app or participating with paid groups that don't have any assurance to deliver a win.
Focus on sports, yes, but say no to games of luck because they will never give us a good chance of winning. That's why they're called games of luck, as the house edge will always win, not every day, but in the long run. Since we as gamblers don't stop when we are winning or losing, the end result will always be us losing. So, just treat games of luck as a fun activity, while games of skill as a job. They should be treated differently.