What is an app? App is an abbrevation for application. Application means to have an "usage". What's the application for you application? If you can state the purpose of your application in a single sentence, chances are that it's compliant with the Appifyer idea of an app: A simple user-friendly application with a single, clearly defined purpose.
The user, especially the Appifyer user, will launch your app with a task at mind. Your goal is to make this task clear and easy to achieve. If the task would be to pick a colour - the user already knows this is the task: Prepare the tools for achieving it as soon as possible - maybe directly. If the user wants to open your app to chat with someone - the goal is the chat box. Help your user achieve it as soon as possible.
Many types of apps are used for a brief moment, then they are idle. With Appifyer, the application could (and should) close when finished - after having delivered results to the user.
For someone wanting to administer the salaries of a thousand-men company, the software for doing so may be a profession and thus very complicated. This is okay. However - for the person seeking to use a simple app that he has been recommended online, it is important that the learning curve is not too steep. An elegant and simple user interface helps promote this simplicity.
Presenting a lot of text works against this goal - instead make the user interaction "natural" by means of positioning controls, and so on. If your application has a lot of settings and configurability, this may be very good for the tenthtime user - but make sure that customization is not mandatory, and that the default settings work well for the majority of users.
To Appify the app, visit the Dev Center in order to register to the forums and as a developer (if you haven't already). Upload the app and present as good information as possible in the provided fields.
If you want to promote your app directly, you can link to it directly by linking to for example http://appifyer.com/apps/#YourApp. If your users may already use Appifyer, you can use the Appify:App URI scheme to create a direct-install link. Please remember to link to Appifyer before doing so though - so that user that are not yet using Appifyer also have a chance to make full use of your application, by first downloading Appifyer.
As for default hotkeys - they can be set if you request it (for example by PMing 'admin' on the forums). As for licensing - you grant Appifyer the right to redistribute your app until further notice, if you upload your app. As for payment - we hope that we can work on a payment method so that all developers that wish to bring in some extra cash or donations can do so, without interrupting the goodwill and simple usage of Appifyer.
So - are you too an Appifyer? Appify it!