I'm only seeing a blank white page
Because appear.in is 100% browser based, it can be affected by the extensions that you have installed on your browser. If you navigate to appear.in and receive a blank white page, this is typically a result of an add blocker or privacy extension.
Depending on what extension you are using, you will want to safelist or whitelist appear.in on your blocker which should resolve the issue. Here are couple popular ones:
I'm using an integration like Trello or Google Docs
If you can access the main appear.in application, but shared content through an integration isn't showing up, it's likely being caused by a third party cookie blocker. Make sure that you allow third party cookies for the site. These are enabled by default in all browsers, but some users chose to disable them. If you have third party cookies disabled, make sure to enable them or safelist the relevant integration domain in your browser.
Find out more about managing your cookie settings here: