「Chibi Dialog」is a uGUI that displays dialogs easily on the screen.
A text input field can also be placed.
I think that it is useful mainly for iPhone and Android.
Click here for the free version without text input field...
If the link is broken, please assume that it was not reviewed. :)

☆ Features ☆
・The background color can be set for each button.
・You can receive a callback when a button is pressed. (The contents of the text input field will be returned as a List.)
・A separate callback is also provided after the dialog is closed.
・The function to close the dialog by tapping on the outside of the dialog is also implemented. This feature can be enabled or disabled.

☆ How to use ☆
1. Add Prefab folder>ChibiDialog to the scene.
2. Add the following code to the variable declaration section of C# and attach it to the GameObject.
//------------------------------
public Chibi.Dialog dialog;
//------------------------------
3. Drag the ChibiDialog added in step 1 to the "dialog" of the script in step 2.
4. Using the demo scene as a reference, write the code to display the dialog.

☆ Notes ☆
If you just want to use dialogs, the free version will work.
This dialog cannot be displayed in multiple layers.
(Because I don't think it is beautiful in terms of UI.)

☆ Update notice ☆
If this dialog is well received, I'll implement an action sheet as well.