gcode-studio will not fix your prints. Its goal is to break them.
Many people have put a lot of effort into ensuring that slicers convert 3D geometry into machine instructions (G-Code) that prints accurately and reliably. Gcode Studio allows you to take that G-Code and transform it in ways that almost certainly will end in ruin. If you are thoughtful and careful this might be an interesting ruin of your print. Otherwise it may be the ruin of your printer.
How to use
Start with a gcode file. This is the file that comes out when you save a print from a slicer application like Cura or MakerBot Desktop. Open the file in a text editor (preferably one that can handle large files). The format isn't very complicated. For the most part it specifies the next X, Y, and Z coordinates of the nozzle, how much filament to extrude (E), and how fast to move (F).
Some example transforms:
if (! isNan(Y) && Z) Y += Z*Z*Z/1000;
Stretch the print toward the front of the printer increasingly as the print rises. Note that Y and Z might not always be defined.
if (!isNaN(X) && !isNaN(Z) && Z > 30) X += 10;
Shift all parts of the print more than 30mm high 10 mm to the right.