apply_filters ( 'infinite_scroll_credit', string $credits )

Notes

Jetpack’s Infinite Scroll module automatically adds some text in the footer created by Infinite Scroll. By default, it includes the name of your theme, a link to WordPress.org (“Proudly powered by WordPress”), and a link to your site’s home page.

You can customize that text thanks to the infinite_scroll_credit filter, like so:

function jetpack_developer_custom_credit() {
 
    $credits = '<a href="http://wordpress.org/" rel="generator">Proudly powered by WordPress</a> ';
    $credits .= sprintf( __( 'Theme: %1$s.', 'jetpack' ), function_exists( 'wp_get_theme' ) ? wp_get_theme()->Name : get_current_theme() );
    $credits .= ' (<a href="http://jetpack.me/">Want to learn more about Jetpack?</a>)';
 
    return $credits;
}
add_filter( 'infinite_scroll_credit', 'jetpack_developer_custom_credit' );