Has anyone read the Terms of Use and Privacy of the Blockfolio app? There's nothing "sneaky" about what it does, which is basically stated there. And of course, you are not "trusting them with your money" if you are using the app, they don't have access to ANY private keys to your coins or anything like it.

My recommendation: read the terms of use before you sign up for any application. And BTW, they don't really know how much you own, just what you decide to "declare" on the app.

Just use under your own responsibility. Or just keep your portfolio data on a spreadsheet.