The answer isn't the same for every app in the category. It turns on one design decision you can see from outside, before you install anything. Does the app track you, or does it read a number your phone already wrote down?
Your phone is already counting your steps
Every modern phone contains a small, low-power motion sensor that counts steps continuously. It runs whether or not you have a step app installed, it is separate from the main processor, and it is designed to sip power. That is why your phone can tell you how far you walked on a day you never opened a fitness app.
Both platforms expose that running total. On iPhone it is HealthKit; on Android it is Health Connect. An app that asks for the total is not starting a measurement. It is reading one that was already happening.
The expensive way to do the same thing
The alternative is to infer movement from location. That means keeping the GPS radio awake, and satellite positioning is among the most power-hungry things an app can ask a phone to do. It's why turn-by-turn navigation visibly drains a battery while a podcast doesn't.
An app that wants your location in order to count your steps has either chosen the expensive way to do a cheap thing, or wants the location for a second reason it has not led with. Either way the permission prompt tells you before you commit. You can settle this one at install time.
What our walking app actually does
Here is ours, taken apart.
Step and Earn reads step totals through HealthKit on iPhone and Health Connect on Android, and asks for exactly one kind of data: the step count. It requests no location permission at all — not while in use, not in the background. On Android it asks for activity recognition, which Health Connect requires before it will answer. On iPhone the HealthKit authorization prompt is the only gate.
There is no background service. The home screen re-reads your step total every twenty seconds while you're looking at it, so the number moves while you walk with the phone in your hand. That timer is canceled the moment the app leaves the screen. Your steps keep accruing while the app is closed, because the phone never stopped counting. The app catches up when you next open it.
The data side
Step counting barely touches your data allowance. Our app keeps a single small record per day — the day's step total, the milestones reached, and a timestamp — which is a fraction of a kilobyte. A year of walking stored this way is smaller than one photo. It's there so a walk survives a reinstall.
What uses data in a reward app is advertising, and specifically video. A rewarded video is a video download, and one of them outweighs a very long time of step syncing. If you're working through bonus ads, doing it on Wi-Fi costs you nothing. Doing it on a metered connection is the one habit in this category that will show up on a phone bill.
How to check any app, including ours
You do not have to take a developer's word for this, including ours. Your phone measures it per app.
- Battery, iPhone. Settings, then Battery. Pick the last 24 hours or the last 10 days, and tap an app to see screen-on time against background time. Background activity on an app you rarely open is the number worth being suspicious of.
- Battery, Android. Settings, then Battery, then battery usage. The same rule applies: compare background against foreground.
- Data, iPhone. Settings, then Cellular, and scroll to the per-app list.
- Data, Android. Settings, then Network and internet, then data usage.
- Before you install. Read the permission list. A step counter that wants location, and a receipt scanner that wants anything beyond the camera and photos, are both worth a second look.
The short version
A reward app that reads your phone's own step counter costs you almost nothing in battery, because the counting was happening anyway. One that tracks your location costs you a great deal. You can see the difference in the permission list before you install, and measure it in your own phone's settings afterwards. In this category, that's one of the few claims you never have to take on trust.
What each of our apps pays you for is set out on how rewards work, and what they ask for and send is taken apart in are reward apps safe.