A few years back, I discovered a unique writing productivity app called “Write Or Die.” Basically, you would set a timer and a wordcount goal, and type in a browser window. If you stopped typing, the screen would gradually turn red and then the app would start playing annoying sounds.
Write Or Die is not especially your friend when you genuinely have no clue what to write next. For that you are better off turning to this technique of author Rachel Aaron’s, where she sits down and tries to figure out what exactly is going on in the next bit she needs to be writing.
Where Write Or Die shines is overcoming that inertia when you know you need to be writing, you know more or less what you need to be writing, but you just can’t seem to pull the trigger. Give it a try sometime, and see if it works for you.