I want to write an apps to post [on hold]

I want to write an apps to post [on hold]

I would like to write a very simple apps that everyone who have downloaded
the apps can post some text (paragraph) so that other people (who also
download the apps) can see the post and may even reply it.
I've already set up a server on my own computer ( using xampp through
(apache, php , mysql) ) and I created a web server that it is OK for me to
upload some post to mySQL and retrieve the post from mySQL on my
localhost. (using php and mostly learn from tutorial)
But the problem is I want to write this on android rather than my own
computer.
Can you guys tell me some algorithm about how to implement the apps ? (Is
it difficult ?)
Or is there anyway I can connect the web server with the apps so that I
can finish the apps
Or may be my algorithm is too stupid and you guys get a much smarter and
easier way to do it?
THANK YOU Very much III
Sorry for the unclear question.(kind of embarrassing) May be using a
example is better. Let's say I want to write an apps like a forum( like
this one stackoverflow). everyone using the apps can ask question and the
question can be seen by other people so that they can reply to it. my
initial plan was first upload user's input onto the database and all
people can read the data in the database so that the communication process
is done. Will it be less confusing ?