Thanks a lot to all of you in the forum for finding bugs and letting me know what to improve.

Here is a list of the improvements :+1:

Fonts in Customizer and Text Formats can now be set in % too
Webfonts are now addable by JavaScript and CSS, for example Adobe Typekit are addable now. Please note as of now this will not display the correct font in the Text Editor.
Added fields for Custom CSS for desktop and mobile version in "Lay Options" → "Misc Options"
The width of an image as a logo can now be set in px too
Gridder: Images are now linkable
If an image was chosen as a logo, it will now appear in the top menu mobile bar
Mobile Text Sitetitle now has same text color as desktop sitetitle
Texteditor: Letter-spacing can now be set for characters too, not just paragraphs
Fixed visual errors for Featured Image mouseover effects
Fixed Customizer close button linking to non-existing page
Fixed jumpy menu points and jumpy logo with certain combinations of mouseover and underline styles
Customizer: more styling options for "Links in Texts"
Customizer: Menu and Site Title's top-space and bottom-space can now be set in %
Customizer: Menu Bar's height can now be set in %
Customizer: Site Title can now have an underline
Customizer: Animation of project title on mouseover can now be turned off
Customizer: New Featured Image mouseover effect: zoom out
Customizer: An image can now be set as a background (only for desktop) with positioning options (default, stretched fixed, center fixed)
Gridder: Fixed a bug that lead to wrong positioning after editing a text
New Logo
Other small bugfixes and improvements