Not sure what you meant by this. The way ST works is that apps are never constantly running, they are run at events or schedules. So if the app is configured to work while in away mode, then the schedules/event will make the app execute it's functions. If it isn't configured to work in away mode then those functions will never be called even if the schedules/events are hit while in away mode.
So say if you've set the app NOT to operate in Away mode and you configure it to change the temp at 8:00pm. Say at 8:00pm the hub in away mode, this app will NOT be called so the temp won't change. Say at 8:15pm you change the mode back to Home, since the schedule has passed it will NOT call the app. This is by design since this Ultimate App is designed to set the temp at a particular time it cannot guess when the next temp change is set (another instance of the app), it could be 1 minute or 1 hour or never, so the app doesn't second guess the user's intention here.
However if you use the 5-2 Thermostat I've published below, that DOES know that there are only X number of schedules set by the user in a day, so if the app returns from Away mode back to Home mode (e.g. as before it's configured not to work in away mode), the app will determine that the last trigger didn't fire and will set the temp to the appropriate temp within the current scheduled time. So say for e.g. you set the return temp to 70 and time to 7:30pm and the sleep temp to 65 and time to 11:00pm, as in the above case since you're in away mode at 7:30pm it won't change the temp, but when you change back to Home mode at 8:15pm, it will detect that the schedule didn't fire and the next temp change is scheduled for 11:00pm, it will change the temp to 70 at 8:15pm (which it the temp set between 7:30pm and 11:00pm). Hope this helps.