Text Viewer App Q

[tekmunki]

I am 'just' getting into app development, so be gentle...

I want to build a very very simple app that opens txt files from email; and then work on formatting them myself.

Do put it simply; I don't mind doing the research- but I'm 'so' green at this I'm not sure where to start.

       TextView tv = new TextView(this);
       tv.setText("Hello, Android");

I assume this is the code I need to research; TextView(filenamevariable.txt)?

My question is this; how do I make my app call and display raw text from any app; for example if I open a txt file in Astro, or from an email attachment- I want my app to be the 'opening app'; Also, I need to know how to make it variable so the app will always look at whatever txt file called the app to start.

I'm OK with vague 'lmgtfy' answers- I'm just at a point where I'm not sure what code I'm looking for- some example code would be great; I really just want to play around with the way text can be displayed from an external file.