Hi Jaipreet - I received 4 of your files for challenges: #143, #142, #118, and #81. I'll email you when the links are updated.
Yes, you're welcome to use our Dropbox share to send your weekly files. Ideally, you should look at moving your courses to your own blog or domain so that your body of work is connected to your brand. But I don't mind hosing your files on our S3 account.
What you could do going forward is this:
1) upload your challenge to
http://tempshare.articulate.com so you get an immediate link to your published file that you can share in the challenges. Tempshare links are good for 10 days so the current challenge participants will be able to view and comment on your work.
2) upload your published files to Dropbox and I'll use those for the recap the following week.