Not willingly? Too many, I unfortunately have to work with Meta's horrifically terrible APIs and every time an issue crops up related to their APIs (nearly daily) I say a silent prayer for that company to disintegrate into nothingness.

Willingly, basically none, or as few as I can realistically manage. I don't have a smartphone other than a burner one with GrapheneOS for my bank app, run linux on everything else and my work MacBook sits idly in the corner somewhere with 0 battery in it despite protesting from my manager.