I know there are several out there that’s supposed to be really nice - both for iOS and Android.
I haven’t used any of them, since I just use ELR That said, ELR will have a mobile app in the near(ish) future Both for Android and iOS (and possibly Windows phone).
Meanwhile - Let’s just get a lot of links to different options I talked to a guy on reddit who made this app - It’s supposed to be good, and he’s actively developing it as well