Hi, I've provided steps below and linked to screenshots and e.g.
1) Create New Project and rename it, then click Load
2) Import Icons from Library, e.g. Icomoon and Linecons
3) Select the first three icons each of Icomoon and Linecons
4) Click the font button at the bottom and download the files.
5) Now click Import Icons red button at top left of the app
6) Upload the saved selection.json file
7) Untitled Set of Icons shows up at the top
8) Add new icons and Download the files
9) Now some of the icons have their unicodes changed, e.g. in the original demo html file, e603 is icon-home, but in the new one, it's icon-tv
10) Screenshot and demo links here
SCREENSHOT ORIGINAL
http://karenmenezes.com/icomoon-unicode/icomoon1-demofile.jpgSCREENSHOT WITH ADDED ICONS, SEE ICON-HOME unicode change
http://karenmenezes.com/icomoon-unicode/icomoon2-demofile.jpg
DEMO HTML FILES
http://karenmenezes.com/icomoon-unicode/icomoon1/demo.html
file:///C:/Users/karen_000/Desktop/icomoon2/demo.html