If you are familiar with web technology building web appi would rmend you use phonegapit help you to build cross platform application not just android and ios it supp windows phoneblackberrymobile web app. It is using htmlcss and javascript phonegap is actually powered by cordova which is container to wrap your app into ios and android and others. Phonegap build is a tool to help you generate your apk file and also ios file and .xap file(for wp) or you can donit manually in your cmd navigate to your project folder undrt platform then run phonegap build androidmand. You will have your ..apk file generated in a new folder called out within your project folder. Note! This is an unsigned apk file. For signed apk file you can resesrch yourself and post an appropriate answer here to supp the others u263au263anOther thaan phonegap xamarin is a good choice for cross platform as well it usimg c# visual studio support it. nHowever i am using phonegap now.! It is Good and easy to learn. It require a lot javascript effort to make a good one but for normal application it will be fine for average JavaScript knowledge.n**according to your situation**nI guess yes there are someone using rails for phonegap as well but i dont know how to implement this. I don't see an ordering system tutorial yet but you can just code your app like how you code a website just that simple.