Issues with Screen Scaling on External Monitor I am using a 2011 Macbook Pro and a horrible Dell Display for some extra space. Because the resolution is horrible on the extra screen, the windows are larger then I would like and Mac OS X does not let me change the scale for it.

Is there an app of something else I could use to solve my problem?
I think changing the screen resolution on the external display could help you in this case. Initially when you open up the Displays Settings from System Preferences. It would look something like this below with a limited set of display resolutions.


This list of resolution is what OS X thinks is the best for your Display. When connecting an external monitor/display, there are chances the aspect ratio is wrong because it's a widescreen monitor. 

Solution


Open the Display Settings from System Preferences on the second monitor. 
Hold the Option key and click on the Scaled button. It should open up a lot more Display resolutions. 



Try finding what's the best option for your display/monitor by trial and error.