No, no app as this isn't a guided breathing technique...just one you can try on your own. It is structured and forces you to focus on what you are doing...which helps me, as my mind tends to drift with other techniques. ;p
If you want something more guided, there is a 13 min video for physical symptoms towards the bottom of our Resource page available...
...but for now, see what you think of this exercise...
The Divided Breath:
Imagine your lungs as having 3 parts. The bottom third, the middle, and top third.
On the inhale fill the bottom third first, then the middle and finally the third. Make sure that this is one continuous breath, but divided, with a slight pause in between each third.
Hold the breath in for 3-5 seconds if possible. Exhale in reverse. First blow out the top third, then the middle, and finally the bottom third of your lungs until all air is expelled. (remember the pauses)
Repeat several rounds for a toatal of about 10 minutes. Practicing this every day will not only give you control and structure to your breathing, it will strengthen and loosen the thoractic muscles, allowing better, more productive breathing, and relieving the chest tightness
Hope you find it helpful as well
S.C.