You might need to do a little hunting to find the backup using a File Manager app, or connect the device to your computer and browse the folder structure.
In OBA v2.9.3 and lower, it should be under the folder OBA Backups, with the file name db.backup.
In OBA V2.9.4 and higher, it should be under your Documents folder, with the file name OneBusAway.backup. Note that sometimes devices have more than one Documents folder.
This could be on the SD card on your device, or on internal storage on your device, depending on your Android version and device manufacturer (it's complicated).
Note that you'll need to put it in the same folder on a new device to be able to "Restore backup" in the app. If you need to load a v2.9.3 backup on v2.9.4, you'll need to rename the from db.backup to OneBusAway.backup and put it in the Documents folder.
The blue dot on the map for my location isn't accurate - it's a few blocks away from my real position
Location information comes directly from your mobile device. The best way to try and fix this is to go to your Android system settings and then "Location,", and make sure that "Mode" is set to "High accuracy (GPS and networks)". After checking/changing this, you might also want to turn your device off and back on again. If the blue dot on the map is facing the wrong direction, you can try calibrating your compass by making a figure 8 with your devices in the air several times. See the "Calibrate your phone or tablet" section of this Google document for more info.
Usually this happens when your device clock or timezone are wrong, or the daylight savings time setting is incorrect. You can check your system clock setting in your Android setting "General ->Date and time", and make sure "Auto time" and "Auto timezone" are checked.
Please be sure to tap on the star next to the stop name, not the route name (see below screenshot). Right now tapping on the star next to the route name (or via the menu after tapping on the arrival time) stars the route, and pins it to the top of the sliding panel. This allows you to quickly tap on stops on the map and see the arrival time for routes you care about. I plan to add a separate “Starred routes” list, although I don’t have a specific timeline for this yet. You can follow progress at OneBusAway#354.
See the Permissions explained page.
OneBusAway Android uses the Maps API v2 in Google Play Services for map rendering, and the map data may have gotten corrupted. You can try restarting your device, and if that doesn't resolve the problem you can clear the cache of Google Play Services using these instructions.
How do I set up the OneBusAway Android app to work with my own OneBusAway or OpenTripPlanner server?
See the Testing with custom OneBusAway and OpenTripPlanner servers page.
My arrival reminders suddenly stopped alerting me and I no longer see the reminder icon on the arrival info. What happened?
Unfortunately you’ll likely need to delete and re-create your alerts. Transit agencies change their schedules around 3-4 times a year and re-generate this data for apps like OneBusAway and Google Maps. Sometimes the trip_ids associated with particular bus arrivals will change. When the IDs change, this breaks alarms because we rely on the trip_id to know when to fire the alarm based on the real-time data. We have no way to match the old and new IDs, so the alarm just stops working. This isn’t an easy problems to solve, but we do have an issue open here to potentially tackle in the future - OneBusAway#333.
There are a number of open issues that are tagged as “Your first PR” that should be a great place for you to start.