Wow that is asking for a lot
There are 2 main things.
Inputs- The images /photos. image recognition is tricky expensive and too
troublesome. Every image pixel or definition taken by diff cameras are different.
Then you need image recogntion software to identify those balls and link to a
central database.
It would be easier have a input screen that has layout of pool table with
gridlines. User touch screen to move the balls to locations on the table. You can
select type of table size, pocket size etc.
Outputs-Then next thing is the outputs i.e. the answers to the inputs above. This
will basically be a database with tonnes of combinations and answers. You have to
add the answers in the database. So eg. Each time inputs (ball positions ) are
entered by user, a search is done in the database and the corresponding answer
will appear on screen. Like eg. if you input cue ball and 2 ball on table, the
answer screen will show line indication direction of shot with some comments etc
Don't even talk about being ambitious and getting answers from tops pros etc LOL
Programmer can code certain straightforward answers or bang shots etc
Probably they can modify and use template of top pool game for standard answers
like straight shot or bang shots etc
In short this is a complex app and not straightforward. Lots of planning,
researching for answers to the inputs cos really you must have answer for every
possble combination of positions inputted by user
If you get USA developer it will cost you tens of thousands dollars at least to
develop such an app. If you get overseas developer like India or eastern Europe
than you can get it done for much less but will be thousands of dollars
If you just want to use for your personal use, it may not be worthwhile doing
unless you are loaded with money. if you want to commercialise and monetise such
an app I doubt whether there is mass demand for such an app.
If it is for your personal use, it may be cheaper to wear a camera on your head
and shoot photos of table and relay that to your advisor who will tell you via
your headphone the shots to make or wear Google Glass