Little endian
The convention where the rightmost Qubit is the zeroth qubit is called little endian. 1
It is used to convert qubits from their binary string representation to the decimal representation, i.e. ${\ket{000}, \ket{001}, \ket{010} …, \ket{111}} \rightarrow \ket 0, \ket 1, \ket 2, …, \ket 7$. In this convention, we label qubits right-to-left, starting with zero. e.g. the decimal representation of a qubit $\ket {b_2, b_1, b_0}$ would be $2^2b_2 + 2^1b_1 + 2^0b_0$.
This convention is used by Quirk and many other Quantum Programming Languages.
Its inverse is called the Big endian.