EDIT: Was able to figure out it was a syncing issue. I'm not sure if it was an issue with using a + in the email address, to allow for a specific address to be used with the iota dot, but if you are using an email with that in, removing it helped with my issues.
If you're having difficulty adding IFTTT, to a Dot, click on "Check it Out" and NOT "Add App". I'm hoping they'll have a better set of instructions for this in the future, and from there you should be able to click on one of the iota labs apps for use. Click and you should be able to select one of the iota dots that you have added.
If you are still having trouble adding, click on the Gear button in the top right hand corner, and either disconnect so you can re-add your connection or click on "Edit connection". Upon clicking on "Edit connection", you should be able to put in your username and password again, so you're able to link the Dots to your account again.
From here, you should have your dots connected again, and you should be able to access them by using an IFTTT app, through setup.
That's what helped me. Hope it helps you. Still would love to know when the "Add App" is back to working properly.