Simple steps to un-install App4Mac's RapidoWrite.
You can lauch the Activity Monitor either by browsing to it in the Finder (/Applicaitons/Utilities/Activity Monitor.app), or, much quicker by using SpotLight as shown here.
Use the Activity Monitor to stop the RapidoWriteService process as shown here.
Open System Preferences and select the Accounts Preference Pane under the System heading.
Start by selecting your own account in the left panel, then make sure the Login Items tab is selected. Find RapidoWriteService in the list, and select it. Finally, remove it by clicking the minus button below the list.
Go to your Applications folder and delete the RapidoWrite app.
Within your home folder you need to delete the following:
1) The folder: Library/Application Support/RapidoWrite
2) The file: Library/Preferences/com.app4mac.RapidoWrite3.plist