Can I use the iPad app for my own Wordpres site?

I have someone with an iPad that tries to go in and edit her posts and has nothing but trouble. I know there’s a wordpress app for the IOS but I don’t know if that can be used on our own website with our own URL or how that works. Can anyone help?

She just needs to be able to log in, see her posts, edit the text, and submit it.

Also, I have it set so they do the Submit for Review so that would have to also work.

Thanks!