I have been a long time user of Yahoo Finance. It had some quirks at times but it was generally a useful app for tracking the market and my portfolio. But after the update on April 8, the app will accurately track the market and portfolio values until about 2 hours after market close and then it regresses to the values at market close on the previous Friday. This pattern repeats on a daily basis. The programmers must have had fun with this one.
Jim4378 about Yahoo Finance: Stocks & News, v3.1.0