Voluntourism programs in Bhutan is very limited as the country itself is very selective about the foreign projects or foreigners engaged in projects in the country. So volunteer works in Bhutan is very limited but but the UN has numerous programs in Bhutan, all coordinated through the UN Development Programme (UNDP), and many different agencies feed into the program. Volunteers are allowed two visitors a year; the visitors must be close relatives and are not subject to the tourist tariff. 

Teaching in Bhutan is the only program run by Bhutan-Canada Foundation if you are willing to work in Bhutan. People from all countries can apply if you are a qualified teacher and the salary is paid by the Bhutanese government.