I think a small backpack looks better than a frame bag for riding MTBs.
*ILE* Apex is really good enough for me and recently I found my favorite way of use. And it’s like this.
*ILE* Phone Holster attached on a shoulder strap. This style can charge your smartphone for all the time.
The charging cable comes out of a zipper port which is originally for a hydration bladder.
This setup works nicely not only for a ride, but also for a travel and your daily life.