How can you display a Unicode character on Android that otherwise appears as ☒? I want to display the character ⮚ on my phone. However, whenever I open any app containing this character, it is displayed as ☒. I am aware that this is due to the font limitations of Android. Is there any way to resolve this?
As of now there is no way to install fonts globally for all applications. I would advice you to write to app developer.

Also this character should be displayed correctly in your web browser. 

In conclusion best way is to approach your application developer by following a feedback channel or writing a review if no feedback or support channel is provided.

Apps like 
WPS Office support this