As far as I know Saleplus is an adware. And I remember it's rather difficult to remove it. To clean it completely you need:
- Uninstall from control panel.
- Delete manifest.json file of the extension using developers mode in Chrome.
- Delete registry keys containing saleplus using regedit.
- After that remove it from browser extensions. I found a really working guides here. The best thing is that there is a video-guide on the site - I mainly used it.