MarketVolume.com has java charts and Android charts with alerts. You should be able to set alert on Stochastic and MACD hstogram and other indicators' levels. They ave sound and email alert. The only problem s that the chart should remain opened on your computer or android.
I'm not sure about alert on MACD Histogram changing direction. In order to set an alert on MACD Histogram changing direction you should
1. apply MA on MACD Histogram
2. calculate difference between MACD Histogram and MA received in #1
3. set alert when the result from #2 crosses 0 (zero line)
For this particular case you should look for a provider who has Histogram applied on MACD Histogram. Plus this provider should have system of alerts.