updated app store preview in readme

Author: hydrahorizon

README.md

@@ -13,7 +13,7 @@ visualized such that the directed paths are aligned along
 the magnetic fields. This creates an easy-to-explore
 visualization of the dependencies around the poles.
 <br><br>
-<p align="center"><a href="https://apps.cytoscape.org/apps/codenetvis"><img src="app-store-preview.png" alt="App Store Preview"><br>Open on Cytoscape app store</a></p>
+<p align="center"><a href="https://apps.cytoscape.org/apps/codenetvis"><img src="app-store-preview-new.png" alt="App Store Preview"><br>Open on Cytoscape app store</a></p>
 
 ### Highlighted Usages