There are quite a few actually. In fact, when you say Flash banner, are you open to the banner being created with standard HTML5/Javascript and CSS as well? I'm only asking because that is where banners are basically headed since Flash isn't supported on all devices these days, and there are a number of free options as well to design animated banners without Flash too.
For Flash, of course there is the official Adobe Flash application. However this is the most expensive route and has the highest learning curve. Some simpler options include:
- Swish. This is a more user friendly Flash animation tool created by some of the folks who originally developed Flash. It's been around for well over 10 years now.
- Sothink SWF Quicker. Similar to Swish, this has also been around for about the same amount of time.
- Koolmoves. Another Swish clone, though not as robust, it also supports non-Flash HTML5/Javascript/CSS animations as well.
- Google AdWords. They offer some free online tools within the AdWords interface to build your own ads based off of pre-made templates.
- Laughingbird Flash Ad Creator. This comes with a bunch of templates to get you started and an easy to use interface. One of the newer but more robust products. Not really ideal for people who want to create everything from scratch though.
On the non-Flash front, the offerings are much newer and have only been around for a few years:
- Google Web Designer. This recently was released this past summer. The title is somewhat misleading as it is more geared towards creating animated banner ads to run on it's AdWords network. It *could* be used to create traditional static web pages as well, but that's not what it's best designed for.
- Adobe Edge Animate. Adobe's official non-Flash animation tool. It too is a work in progress, and they are adding new functionality every few months. What isn't currently supported within the app directly can be handled with external javascript libraries.
- Hippo Animator / Sencha Animator / Nodefire HTML5 Animator. Three different programs by three different companies, but I grouped them all together because my description of them is essentially the same. These are competitors to Adobe Edge Animate. Some of them even offer a few more features than Adobe's product currently. However their costs, particularly Nodefire, make them difficult to recommend when compared to Adobe's offering.