Valid formats are jpgpng (much recommended), png and gif. The best logos are well centered with the logo covering most of the image and transparent background. If you need a quick image editor, you can use the free online image editor [http://aviary.com/apps/flash/aviary/index.aspx?tid=1&Phoenix Phoenix], by Aviary.

It should have transparent background (for best integration in all themes).Valid formats are png, jpg, png and gif. It must not be blurry. '''Most times it's best to zoom in as much as possible to a representative area of the screen, not the whole screen of the app.''' If you need a quick image editor, you can use the free online image editor [http://aviary.com/apps/flash/aviary/index.aspx?tid=1&Phoenix Phoenix], by Aviary.