Here's a brief overview of tools and techniques I have already worked with: - VIPER - as main architecture, MVC - as supplementary; - Working with photos - custom image pickers, cropping, drawing, adding new layers, etc; - Audio Player - fully customizable audio player that has all standard features working in background modes; - Working with databases: Realm, CoreData, Firebase. Setting up, filling in, removing specific data etc; - In app purchases - all kinds; - REST API - get, post, put, patch, delete, uploading and downloading files from server, updating app in background mode, etc;