You should be able to get the interview with the app and phone call. For the interview:

Look sharp.

Have the online app complete and updated to your most recent numbers/info.

Have a good 1 - 2 page resume.

Have your logbooks prepared and updated. Bring them all.

Study the ATP Gliem for the 50 question test.

Be prepared for a 2-on-1 interview. Mostly get-to-know-you, tell-me-about-the-time-that, some technical questions.

BE YOURSELF! Be professional, not canned. Don't come across as arrogant. Be the type of guy you would like to share a flightdeck or crewroom with.

Be prepared for a 15 min sim check. Make sure your instrument skills and scan are up to your certificate (commercial or ATP). Get some sim time before hand. Note - you'll have to have at least 50 hours of flight time in the past six months to be hirable, hopefully most of it multi time.

Be ready to be hired immediately and to go to class quickly. You may not be able to give two weeks notice to your current employer.

Admit to any "problems" in your history. Only a few are disqualifying. Don't hide anything, however. DON'T LIE. They will find out. No surprises!

Remember...most of the guys in the room interviewing with you will disqualify themselves somehow. And the rest will probably get hired.