I would appreciate advice regarding cheap hosting, recommended stacks for implementation and how to learn best practices for secure storage of data.
I'll continue looking on the web for info, however I have a feeling that those on here will have better answers.
I think the best way I can explain it is that this feels the same as contacting a caterer and saying "I have an event with people, what should I serve?" Any good answer would require knowing the type of event, the venue, dietary requirements, number of people, budget etc. Same with you task, but we need to know more about skills, specific functionality, goals, etc.
The actual answer, in my opinion, is that hosting, software stack and secure storage of data aren't a big concern at this point. You have an idea. Turn that into a plan including all the features you think you need to launch a first version of your app. Remove 50% of the features. Remove another 50%. Talk to potential customers. When you have a solid plan, then you can start worrying about how to make it happen. Then build it using whatever software stack you know best.
To get started on hosting, it's hard to beat something like Digital Ocean; $5 or $10 / month and you can run all your test infrastructure (and if you feel like staying with them, push a button and scale as your app demands it). There are a few other good cheap options to get started, such as OVH, if you want a dedicated box; ramnode is interesting.
My biggest issue is that I have not played on machines that are remote site and having to learn the current best practices. It has been about 13 years since I configured Apache.
Digital Ocean sounds like it is worth looking into.
http://html5dev-software.intel.com/ (this used to be called AppMobi / jqmobi, a reduced concept semi-clone of jquery mobile; Intel purchased it)
I've used all three. Sencha has a bit of a steep learning curve, but is nice. The Intel Framework is very easy to get started with; it's pretty fast for what it does; and so long as you're not trying to build the next Instagram, it'll work for a lot of different types of average apps. Using the Intel Framework, the scripting is similar to jquery, it fully supports javascript, and you can easily make ajax calls from the compiled app to a php / python / ruby back-end hosted somewhere else.
For a normal app, the systems side is pretty trivial. A modestly well configured $150 dedicated box will support 99% of all apps these days; and the bottom 50% of apps, based on usage, can be supported on a $20 Digital Ocean style account. If you're going to have a large active user base, then a very well run back-end is obviously that much more important. Today's powerful hardware provides a huge amount of slack on the back-end for a typical app, it's simply unlikely you're going to need to run at hyper efficiency.
I'll bookmark this thread, if you have questions I'd be happy to answer as many as I can here. It can seem like (is) a daunting challenge to build and launch an app.
One question I have in that regard is how to make an app that is most useable for the widest audience?