What software should I integrate to handle the credit card payment on my app?

If you are aiming on iOS and Android with Windows Phone 7/8 as a plus you should use C# as the language and Xamarin Studio as the IDE/Framework. You may also choose to use Visual Studio on Windows as an option. Take a look on their website: http://www.xamarin.com Even Microsoft is using Xamarin to build iOS applications and they have over 400k developers using it. Your application will be native (compiled to the platform you choose) and you are able to use all the native libraries, widgets and UI parts. You will need a cross-platform architecture to be able to reuse code among platforms and using Xamarin you may be able to reuse more than 50-60% of your C# code among platforms. This solution may render the same experience on the devices as on the website, but it enables your applications to deliver much more performance and features than any HTML5 solution. Facebook went from HTML5 to native applications due to performance and user experience limitations (gestures and other platform features are not present using HTML5).

Yes Wix supports a mulitude of APIs to used for various fetch calls for your web pages. If you already have to API's in mind you can venture off within you WIX code to integrate within your application's processes. There shouldn't be any complications getting this done. Please see the link below for more information https://www.wix.com/code/home/api

Create an ideal customer profile. Create some questions that will allow to you survey a potential tester to determine if they fit your profile. Design simple landing page with very clear value proposition that speaks to your ideal customer. Ask for a minimum of information up-front (email), but ask for more info after they commit by submitting the first piece of info. (KISSmetrics does a good job of this on their current website trial signup). Use the their answers to these profiling questions to put the applicants into buckets. Let in the most ideal bucket first, or split them into groups if they're big enough. Try and measure engagement the best you can. Measure qualitative and quantitative data. Schedule calls with your beta testers to find out more, especially with the ones who's user behavior seemed to indicate that they didn't get value from your product. Find out why. Make sure they are indeed your ideal customer. Pick up the phone and get to know your customers inside and out. Meet them in person if possible. Incorporate their feedback quickly and get more feedback. Rinse repeat.

Usually Programmers are only slow when they don't know how to solve a particular problem. So they will spend a lot of time researching and a lot of trial & errors to solve a problem. It is important that before you engage a programmer on a project, you break down the entire project into simple, easy to understand modules. Let him give you an estimate of how many hours he will require to complete each of the modules. Example: a typical site will have a login module, registration, My account, profile etc. So let him estimate how much he will require to do the login. You can go even detail here. (e.g. how much extra time if you were to implement Facebook/Twitter Login?). Once he start developing, track his progress closely and make sure he is following his given timeline. If he goes over his budgeted time on a module, talk with him and see what went wrong. It is often seen that they may be wasting their time on something very insignificant that you may have asked him to implement, but you can totally go by without it too. So by understanding what is taking longer time, you will be able to prioritise things better. You definitely need some tools to get this done. Google Spreadsheet or Excel works just fine. But if you don't mind spending a few bucks there are many agile project management tools that you might look into. Here is a list, google them all and sign up for trials: * AgileZen * Agile Bench * Assembla * AssiTrack * Blossom * Basecamp * Breeze * DoneDone * Eidos * Fogbugz * GreenHopper * Jugggla * Kanbanpad * Pivotal Tracker Or the reason why he is slow can be purely non-technical. Sometime your developer may don't share the same level of enthusiasm as you about the idea that you are working on. They often don't often see the "bigger picture" (since you don't share everything with them explicitly). If you can somehow get them excited about what he is a part of, it will work like a drug :) He will work day and night without questioning you. But you need to work equally as hard as him. The moment he sees that you are the boss and he is just the guy doing work for you -- his mentality will shift from being part of something to being the low paid developer. Ultimately its all about motivation and making him a part of your venture. After all he deserves it, if he is really playing a crucial role in the entire development.

If I was just starting out, I'd consider learning Meteor (https://www.meteor.com/). It's just entered version 1.0 and after working with it for a little less than a year I do have some issues with it but it still makes for a very solid framework that gets you up and running very fast. You would only need to learn Javascript, and you can slowly work your way towards nodejs from there (which Meteor is based on) if you want to, or you could get the basics down and focus on learning design if you prefer.