Hi Andrea!
You're more than welcome to use another tool to participate in the challenges.
We have a few users who regularly share examples created in other tools. Another option is to use PowerPoint to mockup an idea. Whatever you want to use is okay with us.
You can share your examples several ways. You can host your published examples on your own blog or website.
If you don't have a site to host examples, you can use our Dropbox file request link to send me your zipped output:
http://bit.ly/ELHChallenge When you upload your files, please include your first and last name and challenge number in the file name:
DavidAnderson_122.zip
If you're including PowerPoint files, you can attach them to the forums in the Building Better Courses forums:
https://community.articulate.com/forums/building-better-coursesThe forums allow attachments so you can also include a zipped version of your published examples and I'll grab your files there to upload to our server.
I hope that helps!