That's the maximum i got to milk out of the watch. It used to be 1 day 18 hours, last update made it better. You already read my review about it, you're lookimg at anything between 1 day 18 up to 2 days 10 hrs. As for the store, well it's a watch, i don't know what you're exactly looking for in terms of apps, it already has the essentials on it. My advice, the Galaxy watch 3 is far better looking, with the same performance, i just got it to see the difference between OSs, and they're both good, just 3 is waay better looking. Oh one advantage, the new hybrid strap, i bought 2 thinking it will degrade, it's well built, great leather quality and silicone on the inside. 
