If there is magnetic area or metals around you, blue line / Qibla direction deviates. To supress this deviation, shake your device a few times before usage. If the deviation continues, you can switch to Compass Mode in the app.
You device’s Google services must be updated. If you face problems about the update, you can switch to “Compass Mode” for stable results.
100% Prayer & Qibla uses the latest location your device recognises through Google Services. As an example, If your location is A and you close your location on your device’s settings and go to B, your device also app recognises A as your location. So, be sure your location settings are open and up to date.
If you face problems with updating, close and re-open your location settings. You can re-detect you location with black “Find my location” button on the map mode.
Yes, you can use 100% Prayer & Qibla without internet.
Its related to your device’s compass sensitivity. You need to shut down and re-open your device.
Yes, you can make adjustments on Settings > Edit the Prayer Time section. Choose the prayer time you want to be changed, choose minutes (+ or -) and set your new azan times.