Answer 1

That depends on the kind of app you are referring to.

Electron https://www.electronjs.org/ is for desktop apps.

Adobe PhoneGap https://phonegap.com/ is for mobile apps

Apache Cordova https://cordova.apache.org/ supports both mobile and desktop.

Answer 2

Femi Olawole Maybe u'll need a prog lang. Anyway Check this :
https://www.sololearn.com/learn/1439/?ref=app

Answer 3

Martin Taylor The link works fine with me .Maybe bcos iam using the app.

Answer 4

I think you can make Web app using HTML5

Answer 5

You can make app using Javascript libraries like:-
1. Angular JS
2. React JS
3. Vue JS
4. React Native
5. Node JS

Answer 6

Femi Olawole I don't think so. But if your app is static then there is maybe a way to do it. But if you want a dynamic app like SoloLearn, Facebook or something like that where user can register them, it is impossible to create a dynamic app without having good knowledge about programming.