Hello, for:
A. Please follow the steps below:
1- Go to your ftp file manager or filezilla
2- Go to wp-content/themes/sweetdate/page-parts
3- Copy the file home-register-form.php
4- Go to wp-content/themes/sweetdate-child/
5- Create the folder page-parts
6- Paste the file home-register-form.php inside the new folder page-parts in child theme.
7- Edit the file, find the text and change it, then save.
B. Check out this:
http://mobapper.com/index.php
There are a lot more, just google “native app for wordpress”
If you prefer to use andromo.com (free but branded)
When you create the project, each section of the app is called “Activity” to use the app with your wordpress blog, add a Website type Activity to the APP and place your website URL, name the Activity as maybe “Home”
So when users download the app, and click the button Home, it will load your website inside the app, and as user will be using mobile, then it will show the mobile style website. Like this it seems like the app is a native version of your website.
For the last issue, if you want to change the text, betterchange in text mode and not visual, because sometimes it mess with the alignment of the text