@Finasty FlipaClip and Rough Animator are available on Android Phones, I just checked the Google Play Store. It even seems to have a 3D animation app (Prisma3D), which is annoying because outside of Nomad (which is also available on Androids) iPads basically have no good 3D apps despite the extra power (and price), so Android definitely wins there. There are also some free-with-ads apps you can try that might be more what you’re looking for.
Basically I found this out by searching “Animation” on the Google Play Store. As an Apple user, I’m frankly jealous of how many more apps there seems to be on Android devices in general.
jthrash
Hmm…I can recommend quite a few apps for doing traditional frame-by-frame animation, but “splash art” like the example you showed, with auto-tweened animation in between major poses? The best I can probably recommend is ToonSquid, and I think that is only available on iPad since it requires a large screen. Even after, like, 30 years, you still need a powerful PC if you want the computer to do even a fraction of the work for you.
If you are fine drawing EVERY SINGLE FRAME, I can at least easily recommend FlipaClip or RoughAnimator. If you just want to do really simple poses like in the Yasuo Splash Art you showed us, you could probably get away with the free version of FlipaClip, too.
Finasty
Ah jeez, i only have an Android phone