You installed Ilopad when you dragged it to Applications. To remove it, take away its permissions, then move it to the Trash. If you want, you can then also remove your settings.
Remove Ilopad
Remove the permissions before you move Ilopad to the Trash, while macOS can still find it.
Quit Ilopad
Click the Ilopad icon in the menu bar to open its window. Click the menu button, then Settings. If Start on Login is selected, clear it. Then click the menu button and click Quit.
Remove the permissions
Open System Settings › Privacy & Security › Accessibility. Select Ilopad and click − below the list. If macOS asks for your password, type it and click Modify Settings.
If you used pencil mode, do the same in Privacy & Security › Screen & System Audio Recording.
Or remove the two permissions in Terminal. Do this before the next step: macOS must still find Ilopad to remove its permissions.
Move Ilopad to the Trash
Open your Applications folder in Finder. Drag Ilopad to the Trash, then empty the Trash.
Remove your settings
Optional. Moving Ilopad to the Trash leaves your settings behind.
Delete the settings and the Start on Login entry
This deletes your settings, your paired devices and the server key. If you install Ilopad again later, you must pair each device again. In Terminal:
Or, in Finder, click Go › Go to Folder, type ~/Library/Application Support and press Return. Move the ilopad folder to the Trash.
Remove the firewall entry
Only if the macOS firewall is on. Open System Settings › Network › Firewall and click Options. If the list shows Ilopad.app, select it, click − below the list and click OK. macOS asks for your password: type it and click Unlock.