\documentclass{article}

\usepackage{hereapplies}

\begin{document}

\title{Some title}
\author{Some author}

\maketitle

This is concept one. To find this concept applied, please
see \whereapplies{conceptOne}.

This is concept two. To find this concept applied, please
see \whereapplies{conceptTwo}.

\newpage

\hereapplies{conceptOne}This is page \thepage. As you can see, ``concept
one'' applies here.\newpage

\hereapplies{conceptTwo}This is page \thepage. As you can see,
``concept two'' applies here.\newpage

\hereapplies{conceptOne}This is page \thepage. As you can see, ``concept
one'' applies here.\newpage

\hereapplies{conceptTwo}This is page \thepage. As you can see,
``concept two'' applies here.\newpage

\hereapplies[myref]{conceptOne}This is page \thepage. As you can
see, ``concept one'' applies here. This point in the document is
labeled \texttt{myref}.

\end{document}
