Here are my personal recommendations for apps on GrapheneOS:
* App Stores: Sandboxed Google Play, F-Droid (with IzzyOnDroid repository), Accrescent (installable via GOS App Store), Obtainium (for APKs)
* Phone: Default AOSP/GOS phone app
* SMS: Default AOSP/GOS messenger app
* Contacts: Default AOSP/GOS contacts app
* Camera: Default GrapheneOS Camera app
* Browser: Vanadium (default), Vivaldi browser (Play/Obtainium), Firefox/Fennec (Play/F-Droid)
* File manager: Fossify File Manager (Play/F-Droid)
* Gallery: Fossify Gallery (Play/F-Droid)
* Notes: EasyNotes (Accrescent/F-Droid)
* Calculator: OpenCalc (Obtainium/F-Droid)
* Weather: BreezyWeather (Obtainium/Play/F-Droid)
* Mastodon: Moshidon (Obtainium/Play/F-Droid)
* Matrix: Schildichat (F-Droid, own F-Droid repo)
* Sunup: For apps that support UnifiedPush as notification service (Obtainium/Play/F-Droid)