In our collected data,
although we have the detailed GPS information,
the divisions of locations is difficult by GPS coordinates.
Instead,
we identify one location by using the cell ID indicated by cell id entry.
On the one hand, they are easy for processing
On the other hand, the division of different locations by them is more clear than the GPS coordinates.
We build the App matrix in terms of locations by setting rows as Apps and columns as the location IDs.