You enjoy using iStoa for yourself, with your kids or at school. You like the spirit behind free software, you want more mathematic activities, more features.

You can help!

Donating a small amount, even a tiny one, is a nice manifestation of interest and encouragement for further developments. 

After you donate, your name will be listed on this page. If you do not want your name to be shown, please leave a message. Thank you.