I've been getting more and more frustrated that apps I like can't do something weird and bespoke to me that I wish they could so am thinking about just developing my own.

I know a little bit of the basics of coding in Java/XML but not a whole lot. Mostly syntax rules rather than how it's all put together.

I am very experienced with graphical editing software and have begun to mock up what I am after visually, following the Material Design guidelines. And yes, i know WYSIWYG editors aren't that fantastic but I'm wondering if they are more my style.

All the app/s will need to do is display info from other running apps on a card-like interface which I can swipe away. Very pseudo google now, but not google now. I understand Lollipop brought in some simplified code to achieve this but this will obviously mean my app is limited to devices running Lollipop, yes?

Has anyone done a similar leap from nearly complete ignorance to a workable app and have some tutorial references they found useful? There are literally millions of tutorials on the web, but many seem outdated or are poorly written. Is Lynda really the best option?