ios - Can you launch **any** phone app from a web link? -

im making phone automation system web interface. part of looking replace remote controls (tv media center etc) phone.

i have roku media player has remote control ios app, trying launch roku native phone app web interface.

i know possible launch apps via href such this:

<a href="fb://profile">launches native fb app</a> 

but have tried both these fail

<a href="roku://">fails launch native 'roku' app</a>  <a href="roku://">fails launch native 'roku' app</a> 

so have 2 main questions:

1. is possible launch app web link, or app developer need enable function in way?

answer - yes app developer need set url schemer

2. is there way determine url need launch app ie facebook app can launched fb:// can determine anywhere?

answer - there link multiple url schemers popular apps below understanding app developer need release them

thanks

js fiddle in case - https://jsfiddle.net/0znc12bs/

update - point of reference not developing app web service trying connect apps didn't author.

update2 - have been in touch roku support , remote app doesn't support deep linking.

to open app web url app developer need set id (deep linking) setting , url schemas in app

for famous app can find deep linking url net,from can make list open app
else can find on it's site if have written that

list of sites can provides list of url schemas can use open app web :https://stackoverflow.com/a/11155918/4557505