Part 107 UAS pilot reported flying in controlled airspace without authorization.

Narrative

On Day 0 I conducted two UAS flights in two different locations. Each flight lasted less than 5 minutes; the purpose of each flight to collect 2-3 birdseye images at each location. Upon arriving at the first location I checked airspace on B4UFly; received the all-clear; and conducted the flight without incident. When I arrived at the second location I again checked B4UFly; saw the all-clear and conducted the flight. I flew straight up to a height just below 400 feet; collected 2 images and flew straight down; being in the air for less than 3-5 minutes. After the flight; I turned my mobile device back on and noticed that the B4UFly app was now showing that I was just inside an area of controlled airspace (+/- 0.25 miles from the outermost edge of the airspace). Upon further investigation I discovered that when I loaded the app at the second location it had not updated my location and the 'all-clear' that I saw was remaining from the previous flight's location. After opening my mobile device the second time; the app had updated and was showing me just inside of the controlled airspace area. The important take-aways from this experience have been to pay closer attention to the details when checking airspace; ensuring that the app has updated for my current location; and to provide more time for pre-flight planning.