Nice post, I like using blockfolio too, but some people found that it might be recording your portfolio and sending it back to it's servers, heres a post on it - https://steemit.com/bitcoin/@kingscrown/stop-using-blockfolio-app-its-calling-home-with-too-much-info-small-safety-tutorial - but i still use it, because I don't care much about that problem
Yeah the only usage of those data is just for analysing, it doesn't cause any serious problem to me so I don't mind :)