"cleaners" "boosters" and other optimizers are at best useless, at worst, they are their own malware. Stay away form them. You can get root checker from the play store to see if you're rooted. Some off-brand and import phones do come rooted but those aren't common. If you let us know the brand phone and the version of android, we could help a little better.
What makes you think you have a hidden app retrieving messages?