Aren't you satisfied with filters provided by the other apps? Create your own with tools you'll find in Charm!
Tools:
- Tone curve editor
- Brightness
- Contrast
- Saturation
- Exposure
- Vignette
Features:
- About 50 sample filters
- Undo & redo in filter creating tool
- Favorite filters list
- Preserves photos metadata
- iOS 11 & iPhone X support
MetaGear - metadata editor 
Wonderoom Pro 
Photostein 