inotifywait -m "$HOME/bin" -e close_write -e moved_to --format '%w%f' | while read -r fname; do chmod +x "$fname"; done

inotifywait -m "/path/to/bin" -e close_write -e moved_to --format '%w%f' |
   while read -r fname
   do
       chmod +x "$fname"
   done

apt-get install inotify-tools