Hi,

I think that each time you make a change and publish a new version, the platform automatically creates a new versions of the modified resources(e.g css, images etc).
Could you explain why you need to clear the cache on the deivce,
do you need to specifically clear the cache of a single web app?

Try the below method to clear a single page's cache.
Reload a Web page in Mobile Safari twice to clear the cache for the current Web page. Simply press reload, wait for it to finish loading, then reload again.
Source: https://apple.stackexchange.com/questions/27213/is-there-a-quicker-way-to-clear-cache-on-safari-mobile

This clears all the cache and cookies in the iPad.

Settings < Safari < Clear Cookies and Website Data.

but tbh, this is an ipad/apple question ;)