Question: what apps are best for editing pictures?
Answer: Adobe Lightroom — Free (optional subscription)
Photoshop Express — Free.
Snapseed — Free.
VSCO — Free (optional in-app purchases)
Afterlight 2 — $3.
Lens Distortions — Free (optional subscription)
PicsArt — Free (in-app purchases)
Hypocam — Free (in-app purchases)