If Signpost 1.0.1 comes with a built-in uninstaller, or it was installed via the Mac App Store, there is an alternative way you can take to perform the uninstallation.
(1) Apps downloaded from the App Store: Click the Launchpad icon in the Dock, and search for the app in Launchpad interface. Hold down the app icon until all the icons begin to jiggle, then click the delete button that appears in the upper left corner of the icon, and click Delete again in the pop-up dialog to execute the uninstallation.
(2) Apps that have an dedicated uninstaller: Head to the /Applications folder in Finder. Try to open the folder where the app is stored (or its installation package file if you still keep it on your Mac). If there is an items with the name of Uninstall, double-click to launch it and follow the onscreen instructions to complete the removal process.
Step 1: Quit Signpost 1.0.1 as well as its related process(es) if they are still running.
Step 2: Launch Finder on your Mac, and click Applications in the Finder sidebar.
Step 3: Search for Signpost 1.0.1 in the /Applications folder, then drag its icon to the Trash icon located at the end of the Dock, and drop it there. Also, you can right-click/control click Signpost 1.0.1 icon and then choose Move to Trash option from the sub menu.
Step 4: If prompted, enter administrator password and hit OK to allow the change.
Step 5: Choose Finder > Empty Trash from the Menu bar. Or choose right click Trash icon, choose Empty Trash, and Empty Trash again in the pop-up dialog.
Besides, you also can trash the app from the Launchpad interface. During the process, you may be prompted to enter an administrator’s password to make the deletion take effect. Note that the moment you empty the Trash, the app will be permanently removed from your Mac. This act is irrevocable so you must do it with caution.
Why I cannot delete Signpost 1.0.1? Being prompted that “The item Signpost 1.0.1 can’t be moved to the Trash because it’s open”? This message occurs because Signpost 1.0.1 (or its background process) is still running. To quit an app, the common way is to right click app icon on the Dock and choose Quit option. To find out and kill related background process(es), you can run Activity Monitor (located in /Applications/Utilities folder) instead. When uninstalling antivirus/security or malware software, the better option is to reboot your Mac into Safe Mode to prevent automatic launch, and then perform the uninstallation.
EtreCheck is a simple little app to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac.
http://www.etresoft.com/etrecheck
See if it mentions any traces if it.