I am using MAMP on win 8.1 and set up port forwarding in my modem router.
But when i try using my phone or tablet, it just show a html page instead full theme of worpdress.
https://i.sstatic.net/TIl6m.jpg
I try to http://192.168.1.101:8888 or http://192.168.1.101:8888/MAMP and it look like normal as using my PC.
Any idea?
I think you had created your WordPress website in http://localhost:8888 so in your database, the url is http://localhost:8888, not your IP. When you visit the site in desktop, it's ok : The PC can access to the ip and localhost to get ressources like styles and images. But in an another device, it can get the ressources.
You can use the following MySQL queries to update your URL in PHPMyAdmin :
# Change website url
UPDATE wp_options
SET option_value = replace(option_value, 'http://locahost:8888', 'http://192.168.1.101:8888')
WHERE option_name = 'home' OR option_name = 'siteurl';
# Change URL GUID
UPDATE wp_posts
SET guid = REPLACE (guid, 'http://locahost:8888', 'http://192.168.1.101:8888');
# Change medias URL
UPDATE wp_posts
SET post_content = REPLACE (post_content, 'http://locahost:8888', 'http://192.168.1.101:8888');
# Change postmeta URL
UPDATE wp_postmeta
SET meta_value = REPLACE (meta_value, 'http://locahost:8888','http://192.168.1.101:8888');
Be careful to backup your database before make this changes.
If your port is not 8888, just change it in the queries.