First blog for my android application Here I will share with you all about how I build my android application from start to finish(publish). I used a module called waterfall module as it show below: Why I choose this method , because waterfall model used for small to scalable applications, as soon as I finish one step completely I don't have to go back, the only time I go back is when I am adding new levels and that has a very stander structure, currently my application has 24 equations, and now I am preparing for new sets of equations to add on. A preview into to my application, as you read above I built an educational applications, that help student and teacher alike to learn/teach math. My applications has no ads on, I do not collect data or ask for permissions, it has a very simple learning curve Questions are shows, then you thing about the answer. FIRST step: requirement Here I collected all the items and requirement that I needed it, electricity