The main thing I use is the noise level alarm. When Becekett wakes up my phone and the iPad alert me that the baby is up. I then check in to see how baby is doing.
Often the alarm will go off while Barker is using the iPad; he has now discovered how to check in on his little brother. Then I get a bonus alert from Barker announcing, "Beckett crying!" Or "Beckett sleeping!" (Either way it is apparently very exciting.)
Yesterday, I got Beckett from his nap and brought him downstairs while Barker was in the kitchen on his iPad. A few minutes later the alert went off (sometimes lawn maintenance outside will trigger it) so Barker clicked to see his brother. But Beckett wasn't there. Barker announced to Brett, "Beckett gone!!" Brett then assured him that I already had Beckett and was with him on the couch. :)
This morning as I brought Barker downstairs we heard Beckett cough in his room. Barker then exclaimed, "ah Beckett! Look phone!"
Always looking out for his little brother. :) I love how much he cares for him. <3