Olive-backed Sunbird
This is a female. The male has a metallic blue-black chin, throat and chest. The look a bit like a honeyeater and as honeyeaters do eat nectar. They also feed on insects.
They are a small bird at just 100mm and fly directly but often hover as they feed on nectar. If I was quicker I would have got a shot of this one hovering before he flew off.
They live in coastal rainforests, mangroves, tropical parks and gardens. They make high pitched scratchy sounds. They are a common bird and sedentary.