Added new app to the list

Added a new app to the list. It has 10k+ downloads on PlayStore and 4.1 rating.

Author: M1ck0

versioned_docs/version-5.x/used-by.md

@@ -46,6 +46,7 @@ It's impossible to list every single app that uses React Navigation, but below a
 - [Tracker Network for Fortnite](https://apps.apple.com/us/app/tracker-network-for-fortnite/id1287696482)
 - [vrbo](https://www.vrbo.com/mobile/)
 - [Disprz](https://www.disprz.com/) ([iOS](https://apps.apple.com/us/app/disprz/id1458716803#?platform=iphone)) ([Android](https://play.google.com/store/apps/details?id=com.disprz&hl=en_IN&gl=US))
+- [JustCash](https://play.google.com/store/apps/details?id=com.justcash&hl=en&gl=US)
 
 ## Your app?