Is blockfolio app works correctly? I feel that it shows the coin prices than actual value.
As far as I know blockfolio app works correctly. In my case, it accurately shows the coin's average prices on major exchanges. It is useful to monitor bitcoin and altcoin price movements. If you are having problem in using it, just try to uninstall it first, then reinstall it. This should do the trick. If you just want to monitor altcoin and bitcoin price changes, I would recommend using coinmarketcap to you instead of using blockfolio app although they wont notify you when price rises or dumps.