Can't launch or uninstall Disk Drill
From help.cleverfiles.com How to Uninstall Disk Drill


  What’s the correct way to uninstall all the components of Disk Drill? Usually, a Mac user will just move an app to the Trash, and consider the job done. But Disk Drill installs some low-core modules for effective data protection and recovery. So for this type of system-level software, dragging the app to the Trash is not enough.
  
  Here’s the one and only correct way to remove Disk Drill:
  
  
  Launch Disk Drill
  On the menu bar, go to Disk Drill -> Preferences -> General
  Click “Remove Disk Drill”
  That’s all there is to it. But we are already missing you, and hope you will give Disk Drill another try sometime.
  
  
  If for some reason you cannot get to Preferences, there are two ways to delete the Disk Drill components manually:
  
  Alternative #1:
  
  
  Delete Applications/Disk Drill.app
  Delete /Library/LaunchDaemons/com.cleverfiles.cfbackd.plist
  Delete /Library/Application Support/CleverFiles
  (Optional) Go to System Preferences -> Fuse for OSX and click Remove OSXFUSE (Fuse would only have been installed if you opted to mount scanning results as a disk image. If you don’t see it in System Preferences, then it was not installed.)
  Restart your Mac
  
  
  Alternative #2:
  
  
  Go to http://www.cleverfiles.com/getdiskdrill to download the DiskDrill.dmg file.
  Once downloaded, double-click on the DiskDrill.dmg file.
  Do NOT drag the Disk Drill app icon to your Applications folder right now.
  Launch Terminal (Applications/Utilities/Terminal.app)
  Execute the following command in the Terminal:
  sudo /Volumes/DiskDrill/Disk\ Drill.app/Contents/Resources/uninstall
  No need to restart.
  (Optional) Go to System Preferences -> Fuse for OSX and click Remove OSXFUSE (Fuse would only have been installed if you opted to mount scanning results as a disk image. If you don’t see it in System Preferences, then it was not installed.)