Simple Moving Average Cross script. Test on stocks and currency. For stocks test shorter time periods, meaning intra-day time periods such as 3min to 30min and so on to fit what is best. For currency, try longer periods with this model such as day to weeks depending on which currency.
NOTE: Take a look at your Max Drawdowns when testing. This will be the main indicator once you figure out your time period for backtesting. This will also let you know how much money to save and/or hold back in savings for down periods.