How can I monitor and log the connections to my phone's wireless hotspot?
On a rooted phone with super user terminal client like ROM Toolbox Lite(from play store) you can check connected clients using netstat

netstat -ntu | grep ESTAB | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -nr


Checks on ESTABLISHED connections instead of all connections, and displays the connections count for each IP.