Trouble signing in to Yammer app on the iPhone and getting nothing but blank screen?

Most probably your company's Yammer has corporate single-sign-on turned on (so you can use your corporate password to login). The Yammer app seem to not let you login using the Http digest pop-up (a popup dialog to put in your username and password) unlike within a normal web browser.

The solution is simple.

1. login to https://yammer.com
2. on top right, click the "..." (elipsis icon)
3. select apps
4. scroll down and find iPhone
5. click on the 'iPhone' link (not learn more)
6. you will get a temporary password, use this password within the Yammer app. Password is case sensitive

You need to do the same for Yammer on iPad and Yammer Now (the chat).