Travelers can obtain visas at the entry points of Uganda, Rwanda, Kenya and Tanzania. You are advised to secure your visa early enough regardless of them being available at airport. However, you can now obtain your visa upon arrival at Entebbe International Airport or Kigali International Airport. Visas can be obtained at a cost whether you do it earlier or upon arrival at Entebbe airport or Kigali airport. You will be required to present a yellow fever immunization card/certificate and you should have completed filling the application form online and also upload your current photo. Visitors to East African states need valid passport-valid at least 6 months and beyond the end of their period of stay and should also feature sufficient blank pages for visas and immigration stamps.
Please note that nationals of Germany, Sweden, UK, Uganda, Tanzania, Burundi, Democratic Republic of Congo, Mauritius, Hong Kong, South Africa and Canada who may prefer to stay for period of about 90 days may not need visas to get to Rwanda. However, other nationals need to secure valid visa to Rwanda and each visa goes at $35.
Nationals/citizens from commonwealth states do not need visas to get to Tanzania unless they are nationals of Nigeria, India, United Kingdom and Canada.