If you haven't heard of sweatcoin, it's a digital currency unit (a bit like a bitcoin) created by a British company and is generated via an app which counts steps when you are outside (doesn't work inside).
The sweatcoin app pays a rough rate of one sweatcoin for each half mile walked (0.95 sweatcoins per 1000 verified steps). These can then be spent on products and services through their app/website.
You can run the sweatcoin app in the background whilst doing a walk with the iWalk Cornwall app. Since the GPS antenna is already powered-up to supply the iWalk app with locations, running the sweatcoin app even with battery saving mode disabled won't use significantly more battery during a walk. Just remember to re-enable battery saving mode when you not doing a walk.
The one grumble with the sweatcoin app is that it does use a bit of battery on Android when you are NOT walking by trying to detect whether you are (not as much as running the GPS flat-out though). It seems likely this is something that will be improved as the app gets more refined. We've already had a quick chat to @sweatcoin on twitter about it.
With the free subscription (called "mover"), you're limited to "mining" 5 sweatcoins per day. If you are planning on doing longer walks, it might be worth spending 5 sweatcoins on a month's higher membership level ("shaker") that allows you to earn up to 10 per day.
If your first walk is likely to be more than 2.5 miles, a nifty trick so you don't lose out is that if you tap on your username and tap "change" next to the monthly subscription, you can also get the first 30 days of "shaker" membership for free. That means you can mine more than 5 sweatcoins on your first walk, and then you've got some in credit for next time.
If you're planning to install the sweatcoin app, we'd be really grateful if could you do so via this link:
so we get 5 sweatcoins for iWalk Cornwall as a recommendation reward.