"Improved user interface" synonyms for improved could be enhanced, upgraded, optimized. Interface: UI, layout, design. Navigating can be browsing, exploring, accessing.
I will go through each word not in the proper nouns. For "latest," the synonyms could be recent, current, or up-to-date. Wait, the user asked for exactly three synonyms. Let me check each one carefully. MALOY -v1.0- -Color Pictures PRS-
So, applying all these and ensuring not to change proper nouns. Alright, let's put it all together now. "Improved user interface" synonyms for improved could be
Stunning