Jimred... While Naithantu and Tellur are saying they don't want to rain on your parade. I'm sorry but I'm going to just go ahead and do it anyway because I feel it's something not to be taken as offence or in a critical way, but if you're serious about making apps, you can use this to seek direction in your learning.
First of all, you've proposed making an app. That's practically all you have said, feature wise you've mentioned the forums which is a cool idea and really nice. I'd say go for it, could make my life a lost easier at the very least! However you've just named one feature. Do you really have an idea, or do you just want to make an app and enjoy Slap and feel you could combine the two? Not saying it's a bad idea, but you still don't have anything tangible.
Programming is hard work to learn, people (myself included) take 4 year degree's to learn aspects of software development, anyone that promises you easy or no coding isn't really going to be able to deliver much. RunRev will allow you to make very basic apps using their own scripting language with a lot of restrictions. If you're going to make an App, you should learn to do it properly.
To create an actual app, you will need programming knowledge (not to be confused with scripting). C#, C++, Java, would be the main languages to look into. For App purposes I'd say either C# or Java which are very similar in many ways.
But before we look at the development I think it's important to consider the design process. You don't have a design, you've got a small idea with 1 feature so far. You need to be looking at more, you need to break down your program to the nth degree so the developers (you) can develop it properly. Match box programming doesn't work for a big project, and this app is not going to be small. You need a design document with the full concept listed out, break it down from the features and over all idea, down to fonts and colors and then use paper to design the screens and interactions.
This way you can show it to a potential developer partner and they can help with it. They can't help with a project that they don't know about after all
Also if you're looking to incorporate other people to help develop the project and to program it, you're going to need some kind of distribution management system / version control system. Don't even think about emailing the files around or dropbox; after a week your project will be to big to email or take hours to sync to dropbox.
I could go on but I think you have enough to think about. App development is awesome and really fun as well as educational. If you want to make an app then please please by all means do it, I'd love to see the result and give advice where I can. But so far you need to go back to the drawing board and start again. You have to treat the project seriously with documentation and proper management. I'm in the process of building an App at the moment and it's going to take months to complete, maybe even longer.
You also then have deployment to deal with, getting it past Google and Apple for a start to get it on the markets. Then also Microsoft for Window Phones. And if you want to deploy onto more major OS' like Windows, MacOS and Linux (linux isn't a phone OS by the way, not yet anyway) you need to make an entirely new build for those. Each requires it's own set of code, they are totally individual and porting an app can take quite a while. Even if it is quicker than starting from scratch!
Please please do pursue this. It's people telling me this kind of stuff in an upfront way that has made me pursue game development and software engineering. I really encourage you to do so, but I also won't lie to you and tell you that you're going about it the right way. Get on the right tracks and you can go far, even without a degree or proper education around the topic.
HFGL.