How do I create a coordinate system in App Designer?

What I am looking to do is create a program/app that takes in an argument based on where the user selects coordinates from a selected area. Similar to how you'd pick coordinates in Battleship, but with more decimals to it. Is there a component in App Designer that would fit this task (I may have missed something)?

My two ideas on approaching this are as follows:

1. Have a grid layed out with parameters, where the user can click a point, and then the arguments can be taken from there. I could set it up so that it would only work when the point is within bounds, or it might be possible to limit the area of clickability.
2. Use sliders to move a visible point around on the grid. This could then allow the arguments to be taken directly from the slider values, but it would still be important for the app to show specifically where the point is, like with a dot.

Any and all help is most appreciated.

-JL