Currently Online 
I actually don't have too much a problem with the limited tries. I play my five levels and then put it away until tomorrow. What bothers me more is the limited in-game money (and I traded the gems I got in normal gameplay into money), because some later levels are ridiculously hard. The levels with only 5 moves were named, there were also levels where you start with most of the grid frozen so that you can basically do nothing and stuff like that. I tend to use ingame money to buy more moves or a mega-evolution from the start. Also if you want to catch Pokemon, you get into buying Superballs for a lot of ingame money. Didn't pay real money so far and doubt I ever will. But as Rol explained, free-to-play usually has a low percentage of paying customers.
The new Pokemon Rumble is also free-to-play and uses another concept to encourage people to put real money into it.
