This scrip exposes 4 Exponential Moving Average (EMA) indicators which their visibility can be set to a daily or weekly time-frame (aka intervals). Based on your current chart time-frame, the matching EMA indicators come on and off. This helps to have meaningful EMAs relevant to your time internal.
In a traditional 10[unit] EMA indicates a plotted indicator would bear a meaning of a 10 day EMA when in daily and 10 week EMA when in weekly chart which may or may not be useful as some who for example only require a 10 week EMA for thier analysis and wouldn't want to cloud a daily chart with an EMA which won't resemble a valuable output for this particular user.
With EMA+, you can choose to see the 10 week EMA only when your chart is in the weekly time interval, so when switched to a daily interval a 10x EMA is not shown anymore. If you prefer to see a 10 week EMA and a 21 day EMA on the other hand, you will only have 1 EMA shown when in weekly mode which is a 10 week EMA and one EMA when in daily mode with is 21 day EMA.