I created a Google Finance replacement – https://stockdaddy.io – in my spare time. This can track your investments and returns including dividends for stocks and ETFs (real-time) and mutual funds (EOD). It’s basically a pure portfolio tracker without much of the frills of a full finance site. It's meant to be a solid performance tracker and good full screen layout to glance at throughout the day.
IEX whom I would say for the most part is very reliable, although I would only base actual trades off of your brokerage’s data and leave other sources like Yahoo and Stockdaddy for real-time portfolio tracking.