How often do gems appear in Temple Run 2

Bear in mind that Temple Run 2 is a 'free to play' title - they make their money from people buying in-game items, so there are lots of ways to burn through coins and gems.

In this case you can 'gem-power' a power up so that the next time you use it you get more from the power. 1 gem gives you 1 boosted power up use, 2 gems gives you 2 and so on.

If you're going for a long score run you might cash in 5 gems so that you can use the boosted power 5 times.

To be honest, for the amount you get back it's a waste of gems.

I believe, I have got the answer. The score multiplier go like this. When you upgrade it for the first time, it gives one multiplier. When you upgrade it second time, it gives two multipliers and so on. So 5 upgrades will give 15 multipliers in total.