At the moment, we do not have plans to develop a web-based report designer.
You can still give a vote for this feature in our feedback portal to increase its priority - check this post
Telerik by Progress
Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Feedback Portal
and vote to affect the priority of the items