Download the free trial and play with it. Does weather, notams, weight and balance, MSA all in one. NB trial version logs out after 30 mins so don't try it in flight without an alternative.
3G with wifi iPad has a GPS built in and works well.
Do your planning at home in a wifi environment, print your plog and off you go.
I think it's brilliant, just watch the temperature in the cockpit, it shuts down if too hot, and always have a chart with a line drawn on it, same as any GPS.