The following inclusions should be requested from your web app development agency in Singapore.
You should not compromise on the mobile-friendliness of your web applications as more than seventy percent of people who will use your application will do so on a mobile than a desktop. If your web app is designed only to suit a desktop, mobile users will ignore the app forever.
As communication capabilities are vital for all web apps and websites, you should consider allowing the users to ask their queries and get responses quickly using the live chat facility. Although you may have other ways of communicating, small queries would come through this chat facility.
Although SEO is not a feature, it is a necessity for all kinds of websites including web apps. Your web app is going to be live on the internet and will reach a majority of your customers only through the search engines like Google. So, you should ensure that your site ranks at the top of these search engine results pages. SEO is the only option to get higher rankings on Google and you should optimize your web apps accordingly.