Unable to update an app wifi explorer lite

Apps are not held in the iTunes Store, they are held within the Apps Store which is a different application on your system.

Both use the same backend file management elements in your system and depend on your Apple user ID, so make sure you are using the correct user account on your system (which needs to be admin level here).

If your systems drive doesn’t have enough free space or has a corruption. You may need to clean off some stuff and/or reformat the drive and re-install your OS. Don’t forget to make a fresh backup before doing anything on your drive. And lastly make sure you use the proper Apple user ID.