It souds cool and possible to work but I want to remind you that people happily used fake gps apps in even pokemon go to show themselves walking/running. Getting rewards. How can this app block this especially on android, I don't know.
But first of all, there is until now just one big event in September in Vilnius, Lithuania. There is an
Blockchain Run in which every runner will be rewarded with LYM tokens via the Lympo digital fitness wallet.
Your project is nice and you already have some supporters from fitness couches, but are people who work out really the same people that could use blockchain? I bet blockchain is of interest to coders, not sportsmen mainly. I think you should find investors in some major Health organizations. This way you can succeed. Oh, and why only Lithuania and the a couple of States in the US? Why not to try making a deal with app store or something, so that your application could be used worldwide? This way you'll get more chances to attract enough customers. Good luck, the project is still among the best ones!