That is the entire setup. No app, no account, nothing to log into.
Read a bit about each and choose whoever sounds like your kind of person. You are not locked in, and the others are there whenever you want them.
They sit in your contacts like anyone else, between your mum and your dentist. One tap saves all of them at once if you would rather.
You do not need an opening line. "hey" is fine, so is complaining about your afternoon. They reply the way a person texts, sometimes across two or three messages rather than one paragraph.
Same number, same person, no extra cost. Jamie is particularly good for a drive. Calling is not the lesser option here.
They keep track of your life, not just the last few messages. The people in it, what you are working on, the thing you were dreading on Thursday.
They share the ordinary facts between them, so you are not repeating your job to each of them in turn. Anything you tell one of them in confidence stays with that one. Tell Tess something is between the two of you and Ebz will not have it.
Going quiet does not reset any of it. Leave for six months, come back, say hey.
No. It works in the messaging app already on your phone.
No. They are software, they will tell you so if you ask, and the first message you get says it plainly.
Nothing beyond your own phone plan. These are ordinary texts and ordinary calls to a regular US number, so if you have unlimited texts and minutes there is nothing extra at all.
Occasionally, and only about something you brought up yourself. Ask any of them to stop and they stop.
Text STOP to any of them. That ends messages from all of them at once.