Using ProBunker you can keep track of your attendance and by setting your minimum percentage, you can calculate the number of available.
https://play.google.com/store/apps/details?id=com.ssandroid.boltzmann.probunker
Using ProBunker you can keep track of your attendance and by setting your minimum percentage, you can calculate the number of available.
https://play.google.com/store/apps/details?id=com.ssandroid.boltzmann.probunker