I do love the idea of phone charms, though I bet having seven of them on your phone at the same time would drive you nuts pretty fast. However, here's where they are:

Tiki -- in the Base Camp area, in Team Tawaki's tent, on the sleeping bag at the left.

Tui bird disk -- on the path from the Base Camp to the Field, in the grass at the right.

Needle & thread -- at Mossburn, in the woolshed, inside the stall labeled "Instone -- Southland -- 13/11/68," in the straw. (Or is it a haystack? Har har.)

Turtle -- at Doubtful Sound, in the underwater Observatory, on the window ledge at the left.

Another tiki -- at Cromwell, in the sluice area, hanging off the right edge of the large wheel on the ground.

Yet another tiki -- in the Field area, in the Puzzle Palace, the earthquake display (not the Quake Shack, but the little table display with the lights), at the upper left.

Gold ring -- at Lake Te Anau, inside the tunnel; take the left fork, and the charm is at the end on the ground on the left under a light.