GPS and safety
What is GPS spoofing, and how is it different from jamming?
Jamming drowns satellite signals in noise — the phone loses its position. Spoofing transmits fake satellite signals — the phone confidently shows a wrong place, sometimes in another country. Spoofing is the more dangerous one, because the screen looks normal.
How does KeepNav know the signal is fake?
Android gives apps the raw measurements of each satellite. KeepNav computes where every satellite really is from official orbit files and checks: is it above the horizon, does its Doppler shift match, does the time in its signal match the network clock, do GPS, Galileo and the L1/L5 bands agree with each other. A transmitter on the ground cannot fake all of that consistently.
Can I rely on it instead of looking at the road?
No. KeepNav is a navigation aid in beta. Without GPS the position is an estimate with an accuracy shown on screen; it can be wrong. Follow road signs and traffic rules and never operate the phone while driving — use the voice assistant or stop first.
Does the app show where spoofing happens?
Only to you, on your own trips. We deliberately do not publish a public map of interference zones.
Navigating without GPS
How accurate is it without GPS?
With an OBD adapter, when GPS disappears mid-trip: typically 10–40 m, in 9 of 10 cases under ~100 m. Starting already inside a spoofed area: 50–100 m, sometimes more at first. On foot with steps and compass: 15–20 m. Without OBD in a car: only the network position, ~150 m.
Which OBD adapter should I buy?
Any Bluetooth ELM327 adapter works; Bluetooth LE models such as Vgate iCar Pro BLE or OBDLink CX connect faster and more reliably. Most cars from 2001 (petrol) and 2004 (diesel) on have the port. KeepNav only reads speed.
What about bikes and e-scooters?
Fit a Bluetooth cycling speed sensor on the front hub and choose the wheel size in Sensors. Without a sensor, only the network position is available. The two-wheel modes are in beta and not yet tested on the road as much as the car.
Does it work without the internet?
Yes: routing, address search for Kyiv and the regional centres, voice prompts and the voice assistant work offline; the Kyiv map is built in. The internet is used for satellite orbits (once a day is enough), the map outside Kyiv and online address search when the offline one finds nothing.
Does it show traffic?
Not yet — live traffic data for Ukraine is not available from the usual providers. Use the floating button to switch quickly between KeepNav and an app with traffic.
Privacy, price, platforms
Do you collect my location?
No. Your position is computed and stored on your phone. Trip recordings leave the phone only if you send them yourself with “Send to developer”. There is no account, no analytics and no advertising. Details are in the Privacy Policy.
Does the voice assistant listen all the time?
Only after you tap the microphone, or while you have switched on the wake phrase — and then only while KeepNav is on screen, for at most 10 minutes without the phrase. Speech is recognised on the phone; audio is never stored or sent.
How much does it cost?
The beta is free. Our goal is that the core — knowing whether GPS can be trusted and getting home without it — stays free.
Is there an iPhone version?
It is planned. iOS does not give apps raw satellite measurements, so on iPhone the check will be based on plausibility (sensors, odometer, network, time) rather than on the satellites themselves. Navigation, dead reckoning and the voice assistant will come over.
Which Android phones are supported?
Android 10 or newer, 64-bit. The integrity check needs a phone that reports raw GNSS measurements (most phones from 2019 on — Menu → Phone capabilities tells you). The voice assistant needs 6 GB of RAM or more and ~4 GB of free space.