Steps –
1) Upload the appdev-child.zip file (included in the latest version of Appdev) to your WordPress themes dashboard, just like you upload any other theme.
2) Activate the Appdev child theme. Will refer to the parent Appdev theme for most of its function.
3) Edit the functions.php of the child theme and add a function named mo_display_app_button_or_socials() – just copy the contents of the file from line 755 to 768. See the below screenshot to see what you have to copy.
4) Modify the last line of this function –
echo '' . $button_text . '';
to suit your custom needs. Make this change in the function copied to the child theme’s functions.php file. No need to modify the original source.
5) FTP the changed functions.php to the server. You can also edit this file inline under Appearance->Editor tab but I do not recommend it.
Hope this helps.