Most apps couldn't be installed without "hacking" the phone using a ROMPatcher+ or a pre-hacked CFW because official certificates had expired.
SHA2 (SHA256) issue fix · Issue #9 · mrRosset/Symbian-Archive symbian s60v5 rom 2021
The Symbian S60v5 operating system, released in 2008, was a powerhouse for its time, fueling some of the most iconic smartphones of the late 2000s. Despite its age, a dedicated community still supports and develops for this platform. In this blog post, we'll explore the current state of Symbian S60v5 ROMs in 2021, highlighting the best custom ROMs available, their features, and how to get started with flashing your device. Most apps couldn't be installed without "hacking" the
The Preservation and Evolution of Symbian S60v5 ROMs in 2021 released in 2008