Yeah, stuff in spoiler tags are a pain in the butt to read using the mobile app. You have to hit the spoiler mark, which takes you to another page where the text is blacked out (like it appears normally when using an Internet browser), but highlighting it doesn't work like on browser view. So you have to then copy the blacked out portion, and start a thread reply to paste it in just to read the spoiler tags. It sucks.
If there's an easier way to do it in the mobile app, please, let me know.
I could just use Safari on my phone to view the board, but the mobile app loads much faster for me (and I'm an impatient bastard).