Open phones with partner?

For those in long term committed relationships or marriages, what is your policy about phones and mutual access to phone apps, texting, email, etc?

I’ve been married 14 years and “online life” has changed so much in that time. When we got married, I think I still had a blackberry haha. But now every person has (or at least could have) a whole unseen life online. Communities you participate in, advice you give and receive, interests that aren’t immediately obvious because it’s all behind a computer screen.

Because my partner and I are in a very committed relationship and haven’t ever dealt with infidelity, it’s not something I worry about per se in that way. But it is kind of crazy to me how there is a whole part of ourselves we share online anonymously or semi-anonymously.

So I guess I’m just curious how other couples do it? Do you exchange phones freely? Check their phone without their knowledge? Exchange passwords? Have shared accounts? Do you feel guilty “checking in” on them? Or do you even care?