Green Hands USA: America Volunteers

Your iPhone or iPod Touch can help save one of the world's most endangered species.

Just a few hundred mountain gorillas remain the world, half of which live in Virunga National Park in the Democratic Republic of the Congo, where they are under constant threat from roving rebels and people who are destroying the gorillas' natural habitat.

A dedicated team of rangers risks their lives to protect the gorillas -- literally. Dozens of rangers have been killed in the last few years as they heroically tried to protect this disappearing species. Several were killed last month in one of the most brutal attacks to date.

You can stay up to date on the rangers' efforts and the health of the gorillas in Virunga with the new iGorilla iPhone app. The app costs $3.99, and seventy percent of that amount goes directly to the rangers in the field, where it helps to buy medical kits and patrol rations, provide pensions to the widows of slain rangers, or help raise orphaned gorilla babies.

Download the iGorilla app here.

You can also visit the rangers' blog, where you can learn more about their efforts and find more ways to donate, including a new fund they are trying to set up to support widows and orphans of murdered rangers.