This article describes how Peercoin developers are implementing user friendly mobile minting with threshold signatures…
If your coin are in a pool, you are not able to spend some to buy coffee no? How do you get your coins out of a pool when you want to stop pooling?
Of course, you don’t own them,
You ask the rest of the pool to let you go with your coins (and accumulated profits). It all depends on the pool, of course, and the deal you have with the rest of your partners.