This is helpful to spoof websites into showing them a specific screen resolution. But keep in mind that your URL bar and possibly bookmark bar reduce the size of your inner Firefox window detected by websites. So you will have to create a custom preset and add the number of pixels to your desired size.

Love it, nice work.

Le falta un rediseño y un lavado de cara. Tiene opciones interesantes y pese a que tiene presets predeterminados, seria interesante que se añadieran los nuevos y más populares. Más opciones de personalización, etc.

This is exactly what I needed. I haven't had problems with old presets returning (yet). Great for arranging multiple screens as I want them.

Good idea. The UI could be very nice, but doesn't works...

good

The vertical size is limited to 1200px. Just why? I have a 4K display and 1200px is not enough for me for utilizing the entire vertical span.

Constantly loses settings. Pointless.

When I remove lots of old presets and insert new ones i click away and back again and then the old ones come back.