How do I add a second smartphone?

[DrT33]

On my partner's phone, I installed the app, but the process for adding the doorbell to it necessitated a reset and that kicked the doorbell off my phone's app. When I put it back, it was rendered offline on hers. Going round in circles is probably not the correct way. When I sent an invitation, I did not see an offer to connect to an existing system. Did I miss something? 

Doorbell = Video Doorbell 2nd Generation

[jguerdat]

ANy device can only be added once. If it's in your account, it can't be added to another's. As you found, resetting and adding it to the other person's account results in the same thing.

STart fresh, remove the doorbell from any accounts and add it back to yours. Use Settings, People to send an invite to any others. The link in the email may work better if clicked on while using a computer browser rather than their phone. If they already have an account from the previous actions, they just need to log in to accept the invite. Once logged in, they should click on Home and choose the bottom choice. Each user gets their own default Home location so they have to choose yours to be able to see the cameras, etc. I suggest renaming Home to make it more obvious which one to select.

[StephenB]

@DrT33 - another simple path is to have both phones use the same account credentials.