SimBrief is another great online service. It is powered by Navigraph. Is focused on flight planning and everything, that is related to it. It include detailed fuel calculations for over 120 aircraft types, an extensive route database, real-world weather forecasts, current NOTAMs, ETOPS planning, and much more! It is FREE, but slightly limited in this mode. It will only allow you to use some older (outdated) AIRAC cycle for computing the flight route, but you can use otjher services for that. If you have Navigraph subscription, you will be able to use the latest cycle. The flight planning is there very fast and you will get all the required information at one place. You can export the flight plan to many formats and some aircrafts also support to import the flight plan directly from your SimBrief account.