Well, it does not really depend if you doing support by mail or phone, you still spend developer time. For most of the cases 4 hours is more then enough, but fo

Well, it does not really depend if you doing support by mail or phone, you still spend developer time. For most of the cases 4 hours is more then enough, but for example if you app require complex middleware, and you want me to help write it, it may take longer then 4 hours. If so I can provide additional support on hourly basis.