Big Mac Index based on other products or services? The Big Mac Index compares the cost of a McDonalds Big Mac in different currencies around the world. In doing so, it provides:

an informal way of measuring the purchasing power parity (PPP) between two currencies and provides a test of the extent to which market exchange rates result in goods costing the same in different countries

Have any academics, organisations, or think tanks made similarly useful indices based on other product/s or service/s?
Yes there are several other such indexes although none as popular as the Big Mac one.
For example the Economist themselves provide not just Big Mac index but also 'Tall Late Index' based on Starbucks' tall late prices.
Another example is the Bloomberg 'Billy bookshelf index' [ based on Ikea product].
Yet another example is one Australian bank for while used iPod index (although this one was criticized on the grounds that it requires transportation and transportation costs are non-trivial).
Probably you could find more such indexes. In principle any homogenous good can serve as a basis for such index.