Native apps and web apps play by different rules...
... for integrity reasons. (Background tracking is simply deemed too intrusive to only be protected by a popup-box.)
So the differences can be summarized by this table:
Can access the position in the ...
A native app (as downloaded from Google play)
A web app (a web site)
* Native apps run in the background for about 4-5 days after which they closed down by Android to reuse resources.
BLB is a workaround
BLB lets the user send the location (in the background), to any URI (URL) of the users own choice. (Any URI that the user himself/herself has entered).
Currently only a few sites can be used with the app: List of controllable sites.