Nicegram 1.2.4 is available for download:
Download

And it may be received soon via an update.

Key changes:
• Added the ability to clear cache across all accounts via Settings → Advanced → Manage local storage → All accounts → Clear All.
This action clears the cache for all accounts currently in Nicegram, equivalent to using Summary → Clear All for each account.
• Fixed known bugs, including issues with incorrect chat rendering and localization.