Are they standalone apps?

[HerbKramm]

Do Fossify Phone, Messages and Contacts rely on the equivalent apps that come preinstalled on my Samsung phone in order to operate correctly? I'd like to either disable them or remove them altogether, but I'm not exactly sure this is safe.

Much appreciated.

[naveensingh]

They are standalone for the most part, but it depends on what you remove. You must not remove the system phone app if you want emergency calls, because emergency calls unconditionally go through your system phone app.

You should be able to remove the Samsung Messaging and Calendar apps without side effects. Any system service/providers should not be removed/disabled.