I'll go off on a slightly different tangent and state what I think makes a popular RAD tool.
* Focus on quick/easy development in the following areas:
** GUI. It needs to be quick and easy.
** Databases. A tight integration, which focuses on common tasks and makes them easy. I'd like a much tighter level of integration, somewhat like what VB had with Access.
** Networking. While a barebones TCP/UDP implementation is needed, some high level communication libs are necessary.
* Good libraries to simplify common tasks. Examples:
** Handling settings, including such things as common central storage of settings
** Handling security/privileges
** Handling cryptography
** Serialization of objects
* Good debugger. Basically, you need a quick "click run until running"-time. You need good tools to see what's going on under the hood. Breakpoints, conditional breakpoints, singlestepping, call stack watch, performance measuring tools.
* Easy deployment. Building a deployment package should be a simple, integrated procedure.
* Good set of GUI components, which are both according to OS standards and tweakable.
* As speed bump-free as possible. Things should work with as little work as possible, with as little "bureacracy" as possible. The language should be lean, predictable and focus on the problem at hand.
B4X does some of this, but not all, and some things could be better (such as the GUI designer being more WYSIWYG and the debugger being more powerful).
In my experience, RAD is mostly used to make rather simple database frontends, which are mostly GUI and database logic, and not much hardcore number crunching low level stuff. Also, it's increasingly getting more multiplatform, as users expect to be able to access the system from their computer as well as their phon/tablet. If one want a bigger piece of the RAD cake, one has to focus on that market and remove as many obstacles as possible for that kind of programming.
The second largest type of apps developed in RAD, in my experience, is probably the same as above, minus the database. In other words, technically simple apps, with a heavy reliance on GUI, possibly with some networking thrown in. So, solve the problem for the database frontends, and you get these developers as well.
Now, the next problem is "How to get the word out that we have this wonderful tool?". Well, one can't match the marketing budget of the giants, so what remains is old fashioned leg work. Meet people (online or IRL) and speak to them. Show them. Get the people who already use B4X to become "ambassadors" for it (I Think most of us already are...). Get popular dev bloggers to to write about it. Get dev magazines (online or paper) to write about it. Get to speak at dev events. Basically, get it mentioned at every opportunity. It's mostly a matter of getting people to know it exists, so that it becomes one of their available choices in their mind.
