We have 3 pages of documentation here on publishing your app: Overview | Thunkable Docs
The first time I published one of my projects it was challenging and time consuming (but very rewarding!) however, with some practice it gets much easier now.
Under absolutely no circumstances should you share an iOS download link. This is against our terms of services and is not allowed by Apple either. If you do this you risk having your account suspended.
Just to be clear on the costs here, if you want to publish an app from Thunkable to Google Play you need to pay:
Thunkable: $0
Google: $25 one-time fee
To publish a Thunkable project to the App Store you need to pay:
Thunkable: $0
Apple: $99 annual subscription
Once you have paid these fees (for Play Store and App Store) you need to submit your app for review, and if it’s approved by the review teams at Apple and Google it will be published. This typically takes anywhere from a few days to a few weeks.
Wondering if you’ve considered publishing your project as a web app? It’s definitely the fastest way to get your app into your students hands.